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How to Secure SMTP Email Delivery with TLS

hands on a keyboard sending secure email

Secure email sending is a priority for organizations that communicate sensitive data externally. One of the most common ways to send secure emails is with SMTP TLS. TLS stands for Transport Layer Security and is the successor of SSL (Secure Socket Layer). TLS is one of the standard ways that computers on the internet transmit information over an encrypted channel. In general, when one computer connects to another computer and uses TLS, the following happens:

  1. Computer A connects to Computer B (no security)
  2. Computer B says “Hello” (no security)
  3. Computer A says, “Let’s talk securely over TLS” (no security)
  4. Computers A and B agree on how to do this (secure)
  5. The rest of the conversation is encrypted (secure)

In particular:

  • The conversation is encrypted
  • Computer A can verify the identity of Computer B (by examining its SSL certificate, which is required for this dialog)
  • The conversation cannot be eavesdropped upon (without Computer A knowing)
  • A third party cannot modify the conversation
  • Third parties cannot inject other information into the conversation.

TLS and SSL help make the internet a more secure place. One popular way to use TLS is to secure SMTP to protect the transmission of email messages between servers.

Secure SMTP Email Delivery with TLS 

The mechanism and language by which one email server transmits email messages to another email server is called Simple Mail Transport Protocol, or SMTP. For a long time, email servers have had the option of using TLS to transparently encrypt the message transmission from one server to another.

When available, using TLS with SMTP ensures the message contents are secured during transmission between the servers. Unfortunately, not all servers support TLS! Many email providers, especially free or public ones, have historically not supported TLS. Thankfully, the trend is shifting. LuxSci found that most providers now support TLS- approximately 85% of domains tested as of July 2022.

Using TLS requires that the server administrators:

  1. purchase SSL certificates
  2. configure the email servers to use them (and keep these configurations updated)
  3. allocate additional computational resources on the email servers involved.

For TLS transmission to be used, the destination email server must offer support for TLS, and the sending computer or server must be configured to use TLS connections when possible.

The sending computer or server could be configured for:

  1. No TLS: never use it.
  2. Opportunistic TLS: use it if available; if not, send it insecurely.
  3. Forced TLS: use TLS or do not deliver the email at all.

How Secure is Email Delivery over SMTP TLS?

TLS protects the transmission of the email message contents. It does nothing to protect the security of the message before it is sent or after it arrives at its destination. For that, other encryption mechanisms may be used, such as PGP, S/MIME, or storage in a secure portal.

For sending sensitive information to customers, transmission security is the minimum standard for compliance with healthcare and financial regulations. TLS is appropriate to meet most compliance requirements and offers an excellent alternative to more robust and less user-friendly encryption methods (like PGP and S/MIME).

There are different versions of TLS- 1.0 and 1.1 use older ciphers and are not as secure, while TLS 1.2 and 1.3 use newer ciphers and are more secure. When an email is sent, the level of TLS used is as secure as can be negotiated between the sending and receiving servers. If they both support strong encryption (like AES 256), then that will be used. If not, a weaker grade of encryption may be used. The sending and receiving servers can choose the types of encryption they will support. If there is no overlap in what they support, then TLS will fail (this is rare).

What About Replies to Secure Messages?

Let’s say you send a message to someone that is securely delivered to their inbox over TLS. Then, that person replies to you. Will that reply be secure? This may be important if you are communicating sensitive information. The reply will use TLS only if:

  1. The recipient’s servers support TLS for outbound email (there is no way to test this externally).
  2. The mail servers (where the “From” or “Reply” email address is hosted) support TLS for inbound email.
  3. Both servers support overlapping TLS ciphers and protocols and can agree on a mutually acceptable means of encryption.

Unless familiar with the providers in question, it cannot be assumed that replies will use TLS. So, what should you do? Ultimately, it depends on what compliance standards you must meet, the level of risk you are willing to accept, and the types of communications you send. There are two general approaches to this question:

  1. Conservative. If replies must be secure in all cases, assuming TLS will be used is unreasonable. In this case, a more secure method should be used to encrypt the messages in transit and store them upon arrival. The recipient must log in to a secure portal to view the message and reply securely. Alternatively, PGP or S/MIME could be used for additional security.
  2. Aggressive. In some compliance situations like HIPAA, healthcare providers must ensure that ePHI is sent securely to patients. However, patients are not beholden to HIPAA and can send their information insecurely to anyone they want. If the patient’s reply is insecure, that could be okay. For these reasons, and because using TLS for email security is so easy, many do not worry about the security of email replies. However, this should be a risk factor you consider in an internal security audit. Consider nuanced policies that allow you to send less sensitive messages with TLS while sending more sensitive messages with higher security.

What are the Weaknesses of SMTP TLS?

As discussed, SMTP TLS has been around for a long time and has recently seen a great deal of adoption. However, it has some deficiencies compared to other types of email security:

  • There is no mandatory support for TLS in the email system.
  • A receiver’s support of the SMTP TLS option can be trivially removed by an active man-in-the-middle because TLS certificates are not actively verified.
  • Encryption is not used if any aspect of the TLS negotiation is undecipherable/garbled. It is very easy for a man-in-the-middle to inject garbage into the TLS handshake (which is done in clear text) and have the connection downgraded to plain text (opportunistic TLS) or have the connection fail (forced TLS).
  • Even when SMTP TLS is offered and accepted, the certificate presented during the TLS handshake is usually not checked to see if it is for the expected domain and unexpired. Most MTAs offer self-signed certificates as a pro forma. Thus, in many cases, one has an encrypted channel to an unauthenticated MTA, which can only prevent passive eavesdropping.

The Latest Updates to Secure SMTP TLS

Some solutions help remedy these issues—for example, SMTP Strict Transport Security. SMTP STS enables recipient servers to publish information about their SMTP TLS support in their DNS. This prevents man-in-the-middle downgrades to plain text delivery, ensures more robust TLS protocols are used, and can enable certificate validation.

In addition, users can adopt TLS 1.3. NIST recommends that government agencies develop migration plans to support TLS 1.3 by January 1, 2024. LuxSci supports both SMTP MTA-STS and TLS 1.3.

How Secure SMTP TLS Email Works with LuxSci

Inbound TLS

LuxSci’s inbound email servers support TLS for encrypted inbound email delivery from any sending email provider that also supports that. For selected organizations, LuxSci also locks down its servers to only accept email from them if delivered over TLS.

Outbound Opportunistic TLS

LuxSci’s outbound email servers will always use TLS with any server that claims to support it and with whom we can talk TLS v1.0+ using a strong cipher. The message will not be sent securely if the TLS connection to such a server fails (due to misconfiguration or no security protocols in common). Outbound opportunistic TLS encryption is automatic for all LuxSci customers, even those without SecureLine.

Forced TLS

When Forced TLS is enabled, the message is either dropped or sent with an alternate form of encryption if the recipient’s server does not support TLS. This ensures that messages will never be sent insecurely. Forced TLS is also in place for all LuxSci customers sending to banks and organizations that have requested that we globally enforce TLS to their servers.

Support for strong encryption

LuxSci’s servers will use the strongest encryption supported by the recipient’s email server. LuxSci servers will never employ an encryption cipher that uses less than 128 bits (they will fail to deliver rather than deliver via an excessively weak encryption cipher), and they will never use SSL v2 or SSL v3.

Does LuxSci Have Any Other Special TLS Features?

When using LuxSci SecureLine for outbound email encryption:

  1. SMTP MTA STS: LuxSci’s domains support SMTP MTA STS, and LuxSci’s SecureLine encryption system leverages STS information about recipient domains to improve connection security.
  2. Try TLS: Account administrators can have secure messages “try TLS first” and deliver that way. If TLS is unavailable, the messages would fall back and use more secure options like PGP, S/MIME, or Escrow. Email security is easy, seamless, and automatic when communicating internally or with others who support TLS.
  3. TLS Exclusive: This is a special LuxSci-exclusive TLS sending feature. TLS Exclusive is just like Forced TLS, except that messages that can’t connect over TLS are just dropped. This is ideal for low-importance emails that must still be compliant, like email marketing messages in healthcare. In such cases, the ease of use of TLS is more important than receiving the message.
  4. TLS Only Forwarding: Account administrators can restrict any server-side email forwarding settings in their accounts from allowing forwarding to any email addresses that do not support TLS for email delivery.
  5. Encryption Escalation: Often, TLS is suitable for most messages, but some messages need to be encrypted using something stronger. LuxSci allows users to escalate the encryption from TLS to Escrow with a click (in WebMail) or by entering particular text in the subject line (for messages sent from email programs like Outlook).
  6. Domain Monitoring: When TLS delivery is enabled for SecureLine accounts, messages will never be insecurely sent to domains that purport to be TLS-enabled, i.e., TLS delivery is enforced and no longer “opportunistic.” The system monitors these domains and updates their TLS-compliance status daily.
  7. Double Encryption: Messages sent using SecureLine and PGP or S/MIME will still use Opportunistic TLS whenever possible for message delivery. In these cases, messages are often “double encrypted.” First, they are encrypted with PGP or S/MIME and may be encrypted again during transport using TLS.
  8. No Weak TLS: Unlike many organizations, LuxSci’s TLS support for SMTP and other servers only supports those protocol levels (e.g., TLS v1.0+) and ciphers recommended by NIST for government communications and which are required for HIPAA. So, all communications with LuxSci servers will be over a compliant implementation of TLS.

For customers who can use TLS to meet security or compliance requirements, it enables seamless security and “use of email as usual.” SecureLine with Forced TLS enables clients to take advantage of this level of security whenever possible while automatically falling back to other methods when TLS is unavailable.

Of course, using Forced TLS as the sole method of encryption is optional; if your compliance needs are more substantial, you can turn off TLS-Only delivery or restrict it so that it is used only with specific recipients.

If your email use cases are complicated, LuxSci’s flexibility enables the secure sending of emails to any recipient, regardless of their email service provider’s support for TLS. Contact the LuxSci sales team to learn more about our secure SMTP TLS email sending.

Picture of Erik Kangas

Erik Kangas

With 30 years engaged in to both academic research and software architecture, Erik Kangas is the founder and Chief Technology Officer of LuxSci, playing a core role in building the company into the market leader for HIPAA compliant, secure healthcare communications solutions that it is today. An international lecturer on messaging security, Erik also advises and consults on email technology strategies and best practices, secure architectures, and HIPAA compliance. Erik holds undergraduate degrees in physics and mathematics from Case Western Reserve University, and a doctoral degree in computational biophysics from MIT. Erik Kangas — LinkedIn

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LuxSci Automated Email Encryption

“Encryption Optional” Email Will Fail Audits in 2026 and Beyond

For years, healthcare organizations have relied on click-to-encrypt email workflows and secure portals as a practical compromise between usability and compliance. Or in some cases, they simply thought most of their emails did not need to be compliant. In regulated industries where data security and privacy are paramount, this approach was still considered “good enough.”

That era is ending.

As we progress into 2026 and beyond, regulators, auditors, and cyber insurers are sending a clear and consistent message: encryption that depends on human choice is no longer acceptable. It’s already happening. Encryption optional email isn’t merely raising concerns, it’s failing audits outright.

An Email Threat Landscape That’s Changing Faster Than Email Habits

Historically, email encryption was treated as a best practice rather than a hard requirement. If an organization could demonstrate that encryption tools existed and that employees had access to them, auditors were often satisfied. The box was checked, everybody moved on.

Today, the questions auditors ask are fundamentally different. Instead of asking whether encryption is available, they are asking whether sensitive data can ever leave the organization unencrypted. If the answer is yes, even in rare cases, or even accidentally, that’s no longer viewed as an acceptable gap. It’s viewed as inadequate control.

Why 2026 Is a Tipping Point for Email Security

Several forces are converging here in 2026 that make optional encryption increasingly untenable. Regulatory scrutiny around PHI and PII exposure continues to intensify. Breach costs and litigation are rising, with email remaining one of the most common vectors for data exposure and breaches. AI is also changing the game for cybercriminals, and attacks will continue to increase and be more sophisticated. As a result, cyber insurers are tightening underwriting requirements and demanding stronger, more predictable controls.

At the same time, email user behavior is unpredictable and inconsistent, which is a non-starter for data security in today’s world.

Taken together, these trends and behaviors point to a single requirement: email security controls must be automated. They must be enforced by systems, not dependent on employee memory, judgment, or good intentions.

The Reality of “Encryption Optional” in Practice

On paper, optional encryption can sound reasonable. In practice, it creates gaps large enough to open you up to a breach.

Secure portals are a good example. They require recipients to click a link, authenticate, and access content in a controlled environment. While this protects data in transit, and is a better approach than no security at all, it also introduces friction. And people don’t like friction. Senders forget to use the portal. Recipients ask for “just a quick email instead.” Shortcuts are taken to save time. And every shortcut becomes a risk.

Click-to-encrypt systems suffer from a similar problem. They rely on users to correctly identify sensitive data and remember to take action. But people often misclassify information, forget to click the button, or assume someone else has already secured the message. From an auditor’s perspective, this isn’t a training failure. It’s a set-up and control failure.

Email Security Defaults Are the New Normal

The latest message from regulators, auditors, and insurers is clear. If encryption is optional, data vulnerabilities become inevitable.

What can you do?

Below is a quick email security checklist to help you get started. Cyber insurers may require or recommend the following safeguards during the underwriting process, such as:

  • Multi-factor authentication (MFA)
  • Endpoint protection
  • Encrypted backups
  • Incident response planning
  • Encryption protocols for sensitive data in transit and at rest, including PHI in emails

In 2026 and beyond, healthcare organizations and regulated industries will be judged not by what they allow, but by what they prevent. Automated, encrypted email is the new. normal.

Want to learn more about LuxSci HIPAA compliant email? Reach out today.

LuxSci Oiva Health

LuxSci and Oiva Health Combine to Form Transatlantic Healthcare Communications Group

Boston & Helsinki, February 12, 2026 – LuxSci, a provider of secure healthcare communications solutions in the United States, and Oiva Health, a Nordic provider of Digital Care solutions in social and healthcare services, today announced that the companies are joining forces. Backed by Main Capital Partners (“Main”), the combination brings together two complementary platforms and teams, forming a strong transatlantic software group focused on secure healthcare communications.

Founded in 1999, LuxSci is a U.S. provider of HIPAA‑compliant, secure email, marketing, and forms solutions. Its application and infrastructure software enable organizations to securely deliver personalized, sensitive data at scale to support a broad range of healthcare communications and workflows including care coordination, benefits and payments, marketing, wellness communications, after care and ongoing care. Certified by HITRUST for the highest levels of data security, LuxSci serves dozens of healthcare enterprises and hundreds of mid‑market organizations.

Founded in 2010, Oiva Health is a provider of digital care and communications solutions in the Nordics. Headquartered in Finland, with additional offices in Denmark, Norway, and Sweden, Oiva Health offers digital care and digital clinic solutions – including digital visits, secure messaging, online scheduling and appointments, and caregiver communications – serving the long-term care, especially elderly care, and occupational healthcare verticals. The company employs approximately 60 people and has recently expanded across the Nordic region, with a growing presence in Norway and Sweden.

The combination of LuxSci and Oiva Health creates a larger, cross Atlantic group with complementary solutions, serving the U.S. and European markets. Together, the companies offer healthcare providers, payers, and suppliers a comprehensive suite of tools to communicate securely and compliantly, spanning communications, workflows, and virtual care delivery.

Daan Visscher, Partner and Co-Head North America at Main, commented: “We are pleased to announce this cross Atlantic transaction, creating an internationally active secure communications player within the healthcare and home care space. The combined product suite enables healthcare organizations to drive much needed efficiency gains in healthcare provision addressing a global trend of rising costs, aging population, and increasing pressure on resources needed to provide high-quality care.”

Mark Leonard, CEO of LuxSci, said, “We are thrilled to join forces with Oiva Health and believe that together we can truly make a difference in healthcare coordination, access, and delivery. We see an exciting path forward with our customers benefiting from an end-to-end, secure and compliant approach to optimizing both healthcare communications and today’s frontline workers, which we need now more than ever.”

Juhana Ojala, CEO at Oiva Health, concluded, “We look forward to this new chapter together with LuxSci. We are very excited about the strong alignment between our solutions, which especially strongly positions us to expand our flagship Digital Care offering to the high-potential U.S. care market – from care coordination to care delivery to in-home and institutional care.”

Nothing contained in this Press Release is intended to project, predict, guarantee, or forecast the future performance of any investment. This Press Release is for information purposes only and is not investment advice or an offer to buy or sell any securities or to invest in any funds or other investment vehicles managed by Main Capital Partners or any other person.

[END OF MESSAGE]

About LuxSci

LuxSci is a U.S.-based provider of secure healthcare communications solutions for the healthcare industry. The company offers secure email, marketing, forms and hosting, delivering HIPAA‑compliant communication solutions that enable organizations to safely manage and transmit sensitive data. Founded in 1999, LuxSci serves more than 1,900 customers across healthcare verticals, including providers, payers, suppliers, and healthcare retail, home care providers, and healthcare systems, as well as organizations operating in other highly regulated industries. LuxSci is HITRUST‑certified with example clients being Athenahealth, 1800 Contacts, Lucerna Health, Eurofins, and Rotech Healthcare, among others.

About Oiva Health

Oiva Health is a Digital Care provider in the Nordics, offering a comprehensive Digital Platform for integrated health and care services to digitalize primary healthcare, social care, hospital healthcare and long-term care services. The company was founded in 2010 and currently employs approximately 60 people in Finland, Denmark, Norway, and Sweden serving domestic municipalities, customers and partners, such as City of Helsinki, Keski-Suomi Welfare Region, Länsi-Uusimaa Welfare Region in Finland, and Viborg municipality in Denmark with its Digital Care platform. Annually over 5 million customer contacts are handled digitally through Oiva Health’s Digital Care and Digital Clinic platforms.  

About Main Capital Partners

Main Capital Partners is a software investor managing private equity funds active in the Benelux, DACH, the Nordics, France, and the United States with approximately EUR 7 billion in assets under management. Main has over 20 years of experience in strengthening software companies and works closely with the management teams across its portfolio as a strategic partner to achieve profitable growth and create larger outstanding software groups. Main has approximately 95 employees operating out of its offices in The Hague, Düsseldorf, Stockholm, Antwerp, Paris, and an affiliate office in Boston. Main maintains an active portfolio of over 50 software companies. The underlying portfolio employs approximately 15,000 employees. Through its Main Social Institute, Main supports students with grants and scholarships to study IT and Computer Science at Technical Universities and Universities of Applied Sciences.

The sender of this press release is Main Capital Partners.

For more information, please contact:

Main Capital Partners
Sophia Hengelbrok (PR & Communications Specialist)

sophia.hengelbrok@main.nl

+ 31 6 53 70 76 86

HIPAA Compliant Email

Rethinking HIPAA Compliant Email – Not Just a Checkbox

The compliance-only mentality is outdated.

Let’s be honest—when most healthcare organizations think about HIPAA compliant email, it’s usually in the context of avoiding fines or satisfying checklists. And while yes, compliance is critical, viewing it only through the lens of risk management is a missed opportunity.

In reality, HIPAA compliant email, when implemented properly, is one of the most powerful tools for patient and customer engagement. Why? Because it unlocks the ability to leverage protected health information (PHI) safely, enabling personalized, timely, and high-impact email communication that drives better engagement, satisfaction, and outcomes.

What Makes Email Truly HIPAA Compliant?

As a reminder, HIPAA compliant email requires that protected health information (PHI) is safeguarded both in transit and at rest. That means your email provider must:

  • Use encryption at all times
  • Be access-controlled
  • Include audit logs
  • Be stored and transmitted in a secure manner
  • Provide a Business Associate Agreement

Regular email services just don’t cut it. In fact, most consumer or marketing email platforms like Sendgrid or Constant Contact, while great at sending email, are not HIPAA compliant or have limitations when it comes to using PHI in your messages. Even when bolted-on encryption solutions are used, they often lack the flexibility, scalability, and automation needed for safe and effective healthcare email engagement.

LuxSci goes beyond the basics with policy-based encryption, secure TLS, PKI encryption and escrow/secure portal options. LuxSci’s SecureLine™ encryption technology dynamically selects the appropriate encryption method based on recipient capabilities and messaging context and can be configured to enforce secure delivery automatically according to organizational policies. LuxSci also provides the ability to enforce advanced multi-factor authentication. Every message is tracked with full audit trails—no guesswork, no loose ends.

The Real Opportunity – Secure, Personalized Email with PHI

Using PHI to Drive Personalized Messaging
Imagine sending a personalized reminder to a diabetic patient about an upcoming check-up. Or reaching out to new mothers with postnatal care resources tailored to their needs. Or sending automated email workflows to all your members to accelerate and increase new plan enrollments. Or email customer and prospects about a new product upgrade or new service offering. The list goes on. That’s the power of PHI-personalized email—when done securely.

Targeted Segmentation with Sensitive Data
With HIPAA compliant email solutions like LuxSci, you can segment your audience based on real health data with high levels of precision, such as chronic conditions, appointment history, insurance status, health risks, and more, without compromising patient trust or security.

Breaking the One-Size-Fits-All Approach in Healthcare Email
Generic email blasts are over. Modern patients expect personalization. With LuxSci, you can deliver highly targeted, highly secure emails with encrypted content, while staying HIPAA compliant.

Real Business Results from Secure Email

Here’s how secure, personalized email can drive improved results across a range of healthcare communications, including:

  • Increased Patient Appointments and Follow-ups – Sending encrypted, personalized appointment reminders and follow-up notices can reduce no-shows and boost overall appointment volume.
  • Boosting Preventative Care with Outreach Campaigns – Preventative campaigns (think flu shots or cancer screenings) sent securely to the right segments can lead to higher response rates, better health outcomes, and a lower cost of care.
  • Improving Health Plan Enrollments – Targeted email outreach during open enrollment, tailored by eligibility or plan type, and powered by automated workflows leads to higher enrollments and lower call center costs.
  • Driving Awareness and Sales of New Services or Products – Have a product upgrade offer, new wellness program or telehealth service? Send secure, PHI-informed HIPAA compliant email to the right audience for increased sales and faster adoption.
  • Optimize Explanation of Benefits NoticesReplace snail mail with email that’s fast, reliable and trackable, ensuring customers are informed and compliance is met.

The Healthcare Marketer’s Secret Weapon: Using PHI Responsibly

In a world moving away from third-party cookies, first-party data is more valuable than ever, and PHI is the most powerful form of it in healthcare. With secure HIPAA compliant email, PHI doesn’t have to be locked away. Marketers can safely use it to understand patient needs and send relevant, timely messages. PHI-driven segmentation lets you build hyper-targeted campaigns that speak to relevant conditions, unique needs and timely topics, increasing open rates, clicks throughs, and campaign conversions.

Meeting the Personalization Demands of Today’s Patients and Customers

HIPAA-compliant email is no longer just about checking a box. It’s about unlocking the full potential of your patient and customer data to drive better engagement, healthier outcomes, and measurable business results.

In closing, below are some final thoughts on how secure, HIPAA compliant email delivers long-term value for your organization and better connections with your patients and customers, including:

    • Future-Proofing Healthcare Engagement – Patients expect Amazon-level personalization. HIPAA-compliant tools let you meet those expectations securely.

    • Adapting to Data Privacy Regulations Beyond HIPAA – From GDPR to state-level privacy laws, secure communication is no longer optional, it’s foundational.

    • Building Trust Through Secure Communication – Each secure, personalized message sent is a trust-building moment with your patients and customers.

Why LuxSci? The Infrastructure Behind the Performance

With LuxSci’s secure email infrastructure and email marketing solutions, healthcare organizations can confidently personalize communication, reach patients more effectively, and fuel growth with PHI-safe segmentation, messaging, and email automation.

LuxSci takes data security and email performance to the next level by offering dedicated cloud infrastructure for each customer, which means your email campaigns aren’t slowed down by other vendors on shared cloud services and your attack footprint is much smaller. In short, you get higher delivery rates and throughput with proven HIPAA compliance and data security.

The future of healthcare engagement is personal, secure, and performance-driven—and it starts with HIPAA compliant email done right.

Reach out today with any questions or to learn more about LuxSci.


FAQs

1. Is HIPAA-compliant email necessary for marketing communications?
Yes—if your emails include or are based on PHI (like appointment reminders, condition-based messaging, or insurance info), you need HIPAA-compliant email and recipient consent to avoid legal risk and preserve patient trust.

2. Can PHI be used in marketing emails under HIPAA?
Yes, with proper consent and secure, HIPAA compliant infrastructure like LuxSci’s, PHI can be safely used in emails for personalized, segmented campaigns.

3. How does LuxSci ensure high email deliverability for healthcare messages?
LuxSci uses dedicated cloud servers for each customer, active email reputation monitoring, and best-practice configurations to ensure high deliverability rates for sensitive emails.

4. Is LuxSci only for marketing teams?
No—LuxSci supports marketing, clinical, operations, and IT teams by enabling secure, compliant email communication across the entire organization.

5. What types of PHI can I use to segment campaigns using LuxSci?
You can segment based on chronic conditions, visit history, insurance status, provider details, age, gender, location, and more—all while staying fully compliant.

HIPAA compliant email

Most Popular LuxSci Blog Posts of 2025

As we close out 2025, healthcare communicators, IT and compliance leaders, and digital marketers face an ever-changing landscape of security threats, regulatory updates, and technology innovations. At LuxSci, we’re committed to helping you with continuous updates and guidance on the future of secure healthcare communications.

In case you missed it, or need a refresh, below are some of our most popular blog posts from 2025. Enjoy!

1. Improve Email Engagement and Marketing Results with Automated Workflows

Automated workflows are transforming how healthcare organizations engage patients and customers — enabling dynamic, event-driven campaigns that easily scale your outreach and keep you HIPAA compliant. In this post, we introduce LuxSci’s Automated Workflows capability for our Secure Marketing healthcare solution. Learn how sequence-based journeys can personalize outreach and optimize engagement with behavior-based triggers that improve campaign performance — without sacrificing data security.

Read the full post: LuxSci Enhances Secure Marketing with Automated Workflows

2. Healthcare Email Threat Readiness Strategies

Email remains a frontline channel for healthcare communications, and a prime target for cyber threats and criminals. This deep-dive into email threat readiness strategies covers essential practices like continuous monitoring, business continuity planning, and workforce training to mitigate email-borne security risks. Whether you’re responsible for clinical systems, marketing, or enterprise IT, this post provides a strategic playbook to strengthen your defenses, while maximizing your results.

Read the full post: Healthcare Email Threat Readiness Strategies

3. HIPAA Compliant Email — 20 Tips in 20 Minutes

For practical guidance you can apply right now, this on-demand webinar distills 20 key tips for HIPAA-compliant email across technical, legal, and operational domains. Whether you’re refining your infrastructure, improving deliverability, or modernizing your data security posture in 2026, this resource is a time-efficient way to elevate your compliance and security.

Read the post and watch the webinar on demand: HIPAA Compliant Email: 20 Tips in 20 Minutes

4. Is SendGrid HIPAA-Compliant? What You Should Know

Choosing the right email provider matters, especially when Protected Health Information (PHI) is at stake. In this post, we examine SendGrid’s capabilities in the context of HIPAA compliance, outline what it takes to send PHI securely, and offer guidance on evaluating third-party services for secure healthcare email and communication needs.

Read the full post: Is SendGrid HIPAA-Compliant?

5. LuxSci Shines in G2 Winter 2026 Reports

Customer feedback matters to LuxSci. In this post, we share the most recent news about LuxSci’s performance in the G2 Winter 2026 Reports, where we earned 20 badges across categories like Email Security, Encryption, Gateway, and HIPAA-Compliant Messaging. These reviews reflect not just product excellence, but trust from real users, which we work hard to build every day!

Read the full post: LuxSci Shines in G2 Winter 2026 Reports

Looking Ahead to 2026

We look forward to providing more information and insights on secure healthcare communications in the coming year, including the latest on HIPAA compliant email, PHI security, healthcare marketing, threat readiness, and personalized engagement. In the meantime, if you’re not already, follow us on LinkedIn below, and we’ll see you here in 2026!

Follow LuxSci on LinkedIn

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Healthcare Marketing Compliance

What Is Email Marketing For Healthcare?

Email marketing for healthcare is targeted communication strategy that medical organizations use to engage patients, promote wellness services, share health education content, and encourage preventive care while maintaining regulatory compliance and patient privacy protections. This specialized approach helps healthcare providers, payers, and suppliers build stronger relationships with their communities through informative, valuable email communications. Email marketing for healthcare differs from traditional marketing because it must balance promotional objectives with medical ethics, patient trust, and strict privacy regulations. Understanding email marketing for healthcare helps medical facilities develop communication programs that support patient engagement, improve health outcomes, and grow their practices while respecting regulatory requirements and maintaining professional standards.

The Use of Email Marketing For Healthcare

Email marketing for healthcare encompasses several communication types including patient education newsletters, appointment reminders, wellness program promotions, and health screening campaigns. Patient education emails provide valuable health information, seasonal wellness tips, and disease management guidance that helps recipients make informed healthcare decisions. These educational communications build trust and establish healthcare organizations as reliable health information sources.

Appointment and follow-up communications use email to streamline patient care coordination, reduce no-show rates, and improve treatment adherence. Wellness program promotions encourage patients to participate in health screenings, fitness classes, vaccination clinics, and other preventive care activities. Event marketing emails promote health fairs, educational seminars, and community health initiatives that benefit both patients and the broader community. Service line marketing allows healthcare organizations to promote specific departments or specialties to patients who have expressed interest in related services. Women’s health programs, cardiac care services, and orthopedic treatments can be marketed to relevant audience segments based on demographic factors and self-reported health interests rather than protected medical information.

Patient retention campaigns use email to maintain ongoing relationships with existing patients, encouraging regular check-ups, annual screenings, and continued engagement with healthcare services. These campaigns focus on long-term health maintenance rather than immediate sales objectives.

Regulatory Framework and Privacy Considerations

Email marketing for healthcare must comply with HIPAA privacy regulations that govern how protected health information can be used for communication purposes. Healthcare organizations cannot use patient medical records, diagnosis codes, or treatment histories for marketing without explicit written authorization from patients. General health education content can be sent without authorization, but targeted campaigns based on specific health conditions require proper consent procedures.

The CAN-SPAM Act applies to all commercial healthcare emails, requiring truthful subject lines, clear sender identification, valid physical addresses, and functional unsubscribe mechanisms. Healthcare organizations must honor opt-out requests promptly and maintain suppression lists to prevent future unwanted communications. State privacy laws may impose additional requirements that healthcare organizations must research and implement. Business associate agreements become necessary when healthcare organizations use third-party email platforms or service providers to handle patient information during marketing activities. These agreements ensure that vendors maintain appropriate privacy protections and comply with healthcare industry regulations. Healthcare organizations remain responsible for ensuring their email marketing practices meet all applicable regulatory requirements.

Patient consent management requires systems to track when and how patients provided authorization for different types of marketing communications. Organizations need documentation showing patient consent for targeted campaigns and procedures for updating preferences when patients change their communication choices.

Technology Platforms and Integration Requirements

Email marketing for healthcare requires specialized platforms that provide HIPAA compliance features, data encryption, audit logging, and business associate agreements. These platforms must protect patient information during campaign creation, delivery, and performance tracking while maintaining security standards appropriate for healthcare data. Standard consumer email marketing platforms may not provide adequate privacy protections for healthcare communications.

Integration capabilities allow email marketing for healthcare systems to connect with electronic health records, patient management platforms, and appointment scheduling systems. These integrations enable automated campaign triggers based on appointment dates, discharge events, or routine care intervals without exposing sensitive medical information to unauthorized personnel. Single sign-on features allow staff to access email marketing tools using existing healthcare system credentials. List management functionality should support consent tracking, preference management, and compliance reporting requirements specific to healthcare organizations. Segmentation tools need to work with demographic and behavioral data rather than protected health information to maintain privacy compliance. Automated workflows can personalize communications based on publicly available information and patient preferences.

Security monitoring and audit trails provide detailed logging of who accesses patient information, what campaigns are created and sent, and how patient data is used for marketing purposes. These features support compliance demonstrations during regulatory reviews and help organizations investigate potential privacy incidents.

Patient Engagement and Content Strategies

Email marketing for healthcare should prioritize patient value and health outcomes over purely promotional messaging to build trust and encourage long-term engagement. Educational content performs better than sales-focused communications because patients appreciate receiving useful health information that helps them make better healthcare decisions. Content should be evidence-based, medically accurate, and reviewed by qualified healthcare professionals before distribution.

Personalization strategies must balance engagement benefits with privacy requirements and regulatory constraints. Basic personalization using names, preferred languages, and geographic information can improve response rates without requiring protected health information. More detailed personalization based on health interests or conditions requires explicit patient authorization and careful data management procedures. Timing and frequency considerations help healthcare organizations maintain patient engagement without overwhelming recipients with excessive communications. Different types of healthcare emails may require different sending schedules based on urgency, content type, and patient preferences. Appointment reminders need timely delivery, while educational newsletters can follow regular monthly or quarterly schedules.

Interactive content such as health assessment questionnaires, symptom checkers, and wellness challenges can increase patient engagement while providing valuable health information. These interactive elements should collect only necessary information and maintain appropriate privacy protections throughout the user experience.

Performance Measurement and Optimization

Email marketing for healthcare should be evaluated using metrics that reflect patient engagement, health outcomes, and organizational objectives rather than purely commercial success indicators. Appointment booking rates, health screening participation, and patient satisfaction scores provide more meaningful performance measurements than traditional marketing metrics alone. These healthcare-specific metrics demonstrate how email communications support patient care and organizational mission.

Patient feedback collection through surveys, focus groups, and direct communication helps healthcare organizations understand recipient preferences and identify areas for improvement. Regular feedback collection demonstrates commitment to patient-centered communication approaches and provides insights for optimizing future campaigns. Feedback should guide content development, timing decisions, and overall communication strategy adjustments. A/B testing can improve campaign performance by comparing different subject lines, content formats, sending times, and call-to-action approaches while maintaining compliance requirements. Testing should focus on elements that affect patient engagement and health outcomes rather than manipulative tactics that might undermine patient trust.

Long-term performance analysis helps healthcare organizations understand the cumulative impact of their email marketing efforts on patient relationships, care utilization patterns, and health outcomes. This analysis supports continuous improvement initiatives and demonstrates the value of patient communication investments to organizational leadership and stakeholders.

HIPAA Emailing Patient Information

What is a HIPAA Compliant Email Service?

A HIPAA compliant email service is a secure email platform that meets all Health Insurance Portability and Accountability Act requirements for protecting patient health information during electronic communications. These specialized email platforms implement administrative, physical, and technical safeguards required under the HIPAA Security Rule, enabling healthcare providers, business associates, and covered entities to transmit protected health information electronically without violating federal privacy regulations. Unlike standard email services that lack encryption and access controls, a HIPAA compliant email service incorporates end-to-end encryption, audit logging, user authentication protocols, and business associate agreements to ensure that all electronic communications containing individually identifiable health information remain secure throughout transmission and storage.

Why a HIPAA Compliant Email Service is Necessary

Healthcare organizations that handle protected health information must comply with stringent regulatory requirements when using electronic communication systems. The HIPAA Security Rule mandates that covered entities implement appropriate administrative, physical, and operational safeguards to protect the confidentiality, integrity, and availability of electronic protected health information. When healthcare providers use email to communicate about patients, discuss treatment plans, or transmit medical records, these communications become subject to HIPAA regulations because they contain individually identifiable health information. Standard consumer email services like Gmail, Yahoo, or Outlook do not provide the necessary security controls required for healthcare communications, creating potential compliance violations that can result in substantial penalties from the Office for Civil Rights.

A HIPAA compliant email service handles these regulatory challenges by implementing encryption protocols, access controls, and audit mechanisms required under federal law. These specialized platforms ensure that all email communications are encrypted both in transit and at rest, preventing unauthorized access to protected health information even if messages are intercepted during transmission. Healthcare organizations using a HIPAA compliant email service can establish proper business associate agreements with their email provider, creating the legal framework required for third-party handling of protected health information.

Safeguards in Healthcare Email Systems

The administrative safeguards required for a HIPAA compliant email service involves policies, procedures, and controls governing how healthcare organizations manage email communications containing protected health information. Healthcare entities implementing secure email systems need to establish clear protocols for user access management, ensuring that only authorized workforce members can send, receive, or access emails containing patient information. These administrative controls include implementing role-based access permissions, establishing procedures for granting and revoking email access when employees join or leave the organization, and maintaining detailed documentation of all email-related policies and training programs.

Workforce training is another important aspect of safeguards for healthcare email communications. Organizations using a HIPAA compliant email service need to educate their staff about proper email usage, including guidelines for when it is appropriate to include protected health information in electronic communications, how to properly send secure emails, and procedures for reporting potential security incidents or unauthorized access attempts. This training ensures that healthcare workers understand their responsibilities when using secure email systems and helps prevent inadvertent disclosure of protected health information through improper email practices. Refresher training and updates to email policies help maintain compliance as technology and regulations evolve, while documented training records provide evidence of organizational commitment to protecting patient privacy.

Encryption Standards

Operational safeguards are the core of any HIPAA compliant email service, delivering the security controls necessary to protect electronic protected health information during transmission and storage. End-to-end encryption represents the most important technical safeguard, ensuring that email messages containing patient information are encrypted using strong cryptographic algorithms before transmission and can only be decrypted by authorized recipients. Modern secure email platforms implement Advanced Encryption Standard (AES) with 256-bit keys or similar encryption methods that meet current industry standards for protecting sensitive healthcare data. This encryption protects against unauthorized interception of email communications, even if messages are captured while traveling across public internet networks.

Access control mechanisms within a HIPAA compliant email service prevent unauthorized users from accessing protected health information stored in email systems. Multi-factor authentication requirements ensure that users must provide multiple forms of verification before accessing their secure email accounts, adding additional protection beyond simple username and password combinations. Automated audit logging captures detailed records of all email activities, including message sending and receiving times, user login attempts, and any administrative actions performed within the system. These audit logs provide healthcare organizations with the documentation necessary to demonstrate compliance during regulatory audits while also enabling detection of potential security incidents or unauthorized access attempts.

Digital certificates and secure email gateways provide additional technical safeguards by verifying the identity of email senders and recipients while ensuring that messages can only be transmitted between properly authenticated parties. Message integrity controls detect any unauthorized modifications to email content during transmission, while secure backup and disaster recovery systems protect against data loss while maintaining encryption standards for stored communications.

Physical Safeguards for Email Infrastructure

Physical safeguards protect the computer systems, workstations, and electronic media used to store and process emails containing protected health information. A HIPAA compliant email service provider maintains secure data centers with appropriate physical access controls, environmental protections, and equipment safeguards to prevent unauthorized access to servers hosting healthcare communications. These data centers implement multiple layers of physical security, including biometric access controls, security cameras, environmental monitoring systems, and redundant power supplies to ensure continuous protection of stored email data.

Healthcare organizations using secure email services also need to implement appropriate physical safeguards at their own facilities. Workstations used to access a HIPAA compliant email service need proper positioning to prevent unauthorized viewing of email content, automatic screen locks when users step away from their computers, and secure disposal procedures for any printed email communications containing protected health information. Mobile devices accessing secure email systems require additional protection through device encryption, remote wipe capabilities, and secure container technologies that separate healthcare communications from personal data on employee smartphones or tablets.

Environmental controls within healthcare facilities help protect against physical threats to email security, including proper climate control for computer equipment, fire suppression systems that won’t damage electronic devices, and backup power systems to maintain email availability during emergencies. Regular maintenance and monitoring of physical infrastructure ensure that protective measures remain effective while documentation of physical safeguards provides evidence of organizational commitment to protecting patient information stored in electronic communications.

Business Associate Agreements & Vendor Management

Healthcare organizations selecting a HIPAA compliant email service need to establish proper business associate agreements that define the legal responsibilities and obligations of both parties regarding protected health information. These agreements specify how the email service provider will protect patient data, what uses and disclosures are permitted, how security incidents will be reported, and what happens to protected health information when the business relationship ends. A comprehensive business associate agreement for email services addresses encryption requirements, audit logging standards, employee training obligations for the service provider, and procedures for responding to regulatory inquiries or patient requests for information.

Vendor due diligence processes help healthcare organizations evaluate potential email service providers to ensure they can meet HIPAA compliance requirements. This evaluation includes reviewing the provider’s security certifications, examining their data center facilities and security controls, assessing their incident response capabilities, and verifying their experience with healthcare industry regulations. Ongoing vendor management activities include regular security assessments, review of audit reports and compliance documentation, monitoring of service level agreements, and periodic evaluation of the email provider’s ability to adapt to changing regulatory requirements.

Healthcare organizations also need to consider the geographic location of email servers and data processing facilities when selecting a HIPAA compliant email service provider. Some providers offer options for maintaining all protected health information within United States borders, while others may provide additional privacy protections through international data processing agreements. Contract negotiations address liability allocation, insurance requirements, termination procedures, and dispute resolution mechanisms to protect healthcare organizations from potential compliance violations or security incidents related to their email communications.

Implementation and Migration

Healthcare organizations transitioning to a HIPAA compliant email service need careful planning to ensure seamless migration while maintaining security throughout the process. Implementation strategies address user training requirements, data migration procedures, integration with existing healthcare information systems, and testing protocols to verify proper security controls before going live with the new email system. Organizations need to develop detailed project timelines that account for user adoption challenges, potential technical issues, and regulatory compliance verification activities while minimizing disruption to patient care activities.

Migration planning includes inventory of existing email communications containing protected health information, assessment of integration requirements with electronic health record systems and practice management software, and development of backup procedures to protect against data loss during the transition process. Healthcare organizations need to coordinate with their chosen email service provider to establish proper configuration settings, implement appropriate security controls, and conduct thorough testing of encryption, access controls, and audit logging capabilities. User acceptance testing ensures that healthcare workers can effectively use the new secure email system while maintaining productivity and patient care quality.

Post-implementation activities include monitoring of email security controls, regular review of audit logs and compliance reports, periodic security assessments to identify potential vulnerabilities, and continuous training programs to help users adapt to new email features and security requirements. Healthcare organizations benefit from establishing internal email governance committees that oversee compliance activities, evaluate new email features or capabilities, and coordinate responses to security incidents or regulatory changes affecting electronic communications.

email deliverability

What is Email Deliverability?

Email deliverability refers to the ability of emails to reach recipients’ inboxes successfully without being filtered into spam folders or blocked entirely by email service providers. This metric involves the entire journey an email takes from sender to recipient, including authentication protocols, sender reputation, content quality, and recipient engagement patterns. For healthcare organizations managing patient communications, provider networks, and supplier relationships, understanding email deliverability is highly important given the sensitive nature of healthcare data and the need for reliable communication channels.

How Email Service Providers Filter Messages

Email service providers use sophisticated algorithms to evaluate incoming messages and determine their appropriate destination. These systems analyze multiple factors simultaneously, including sender authentication records, message content, sending patterns, and recipient behavior. The filtering process occurs in real-time, with providers like Gmail, Outlook, and Yahoo applying machine learning models trained on billions of email interactions to identify potential spam or malicious content. Authentication plays a large role in this filtering process. Providers verify sender identity through SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) records. Healthcare organizations without properly configured authentication often find their appointment reminders, lab results, or billing communications relegated to spam folders, disrupting patient care workflows and administrative processes.

Sender Reputation and Its Impact on Healthcare Communications

Sender reputation functions as a digital credit score for email domains and IP addresses, influencing whether healthcare organizations can reliably reach patients, providers, and business partners. Email service providers maintain reputation databases that track sending behavior, bounce rates, spam complaints, and recipient engagement over time. A single domain or IP address with poor reputation can affect email deliverability across an entire healthcare network. Healthcare entities take on reputation challenges due to the nature of their communications. Patient appointment reminders sent to outdated email addresses generate high bounce rates, while automated billing notifications may receive spam complaints from recipients who forgot they subscribed to such communications. These factors can gradually erode sender reputation, making it increasingly difficult to reach patients with time-sensitive medical information.

Protocols for Healthcare Email Deliverability Security

Modern email deliverability depends heavily on proper implementation of authentication protocols that verify sender identity and prevent email spoofing. SPF records specify which mail servers are authorized to send emails on behalf of a domain, while DKIM adds cryptographic signatures to verify message integrity. DMARC ties these protocols together by instructing receiving servers how to handle emails that fail authentication checks. Healthcare organizations must configure these protocols carefully to avoid authentication failures that could block legitimate patient communications. A misconfigured SPF record might prevent appointment confirmation emails from reaching patients, while improper DKIM setup could cause lab result notifications to be filtered as spam. These authentication failures can have serious implications for patient care, particularly when dealing with urgent medical communications or time-sensitive treatment instructions.

Content Quality and Compliance Considerations

Email content quality directly affects email deliverability, with providers using advanced algorithms to evaluate message structure, language patterns, and formatting for spam indicators. Healthcare organizations must balance informative content with deliverability requirements, ensuring that medical communications reach their intended recipients without triggering spam filters. This balance becomes particularly challenging when dealing with complex medical terminology, prescription information, or insurance-related content that may resemble spam to automated filtering systems. HIPAA compliance adds another element of complexity to healthcare email content, as organizations must protect patient information while maintaining effective communication channels. Emails containing protected health information require extra security measures and careful content formatting to avoid both compliance violations and deliverability issues. The challenge is in creating compliant, informative communications that also pass through increasingly sophisticated spam filters.

Email Deliverability Performance

Tracking email deliverability metrics provides healthcare organizations with the data needed to identify and address communication issues before they impact patient care or administrative operations. Key metrics include delivery rates, bounce rates, spam complaint rates, and inbox placement percentages across different email providers. These metrics help organizations understand how their communications perform across various platforms and identify potential problems with specific communication types or recipient segments.

Healthcare organizations should establish monitoring systems that track deliverability performance across different communication channels, including patient portal notifications, appointment reminders, billing communications, and provider-to-provider messages. This approach helps identify patterns that might indicate authentication issues, content problems, or reputation concerns that could affect the organization’s ability to communicate effectively with patients and business partners.

encrypted email transmission

Is the Email Encrypted? How to Tell if an Email is Transmitted Using TLS

SMTP TLS encryption is popular because it provides adequate data protection without creating a complicated user experience for email recipients. Sometimes, though, the experience is too seamless, and recipients may wonder if the message was protected at all.

Luckily, there is a way to tell if an email was encrypted using TLS. To see if a message was sent securely, we can look at the raw headers of the email. However, it requires some knowledge and experience to understand the text. It is actually easier to tell if a recipient’s server supports TLS than to tell if a particular message was securely transmitted.

To analyze a message for transmission security, we will look at an example email message sent from Hotmail to LuxSci. We will explain what to look for when decoding the message headers and how to tell if the email was transmitted using TLS encryption.

An Example Email Message

First, we must understand how an email message typically travels through several machines on its way from the sender to the recipient. Roughly speaking:

  1. The sender’s computer talks to the sender’s email or WebMail server to upload the message.
  2. The sender’s email or WebMail server then talks to the recipient’s inbound email server and transmits the message to them.
  3. Finally, the recipient downloads the message from their email server.

It is step 2 that people are most concerned about when trying to understand if their email message is transmitted securely. They usually assume or check that everything is secure and OK at the two ends. Indeed, most users who need to can take steps to ensure that they are using SSL-enabled WebMail or POP/IMAP/SMTP/Exchange services so that steps 1 and 3 are secure. The intermediate step, where the email is transmitted between two different providers, is where messages may be sent insecurely.

To determine if the message was transmitted securely between the sender’s and recipient’s servers (over TLS), we need to extract the “Received” header lines from the received email message. If you look at the source of the email message, the lines at the top start with “Received.” Let’s look at an example message from a Hotmail user below. The email addresses, IPs, and other information are obviously fake.

LuxSci:

The Outlook email was sent to a LuxSci user. The Received headers appear in reverse chronological order, starting with the server that touched the message last. Therefore, in this example, we see the LuxSci servers first.

Received: from abc.luxsci.com ([1.1.1.1])
	by def.luxsci.com (8.14.4/8.13.8) with ESMTP id r7JEfLgH003867
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT)
	for <user-xyz@def.luxsci.com>; Mon, 19 Aug 2019 10:41:21 -0400
Received: from abc.luxsci.com (localhost.localdomain [127.0.0.1])
	by abc.luxsci.com (8.14.4/8.13.8) with ESMTP id r7JEfK0Z030182
	for <user-xyz@def.luxsci.com>; Mon, 19 Aug 2019 09:41:20 -0500
Received: (from mail@localhost)
	by abc.luxsci.com (8.14.4/8.13.8/Submit) id r7JEfKXD030178
	for user-xyz@def.luxsci.com; Mon, 19 Aug 2019 09:41:20 -0500
Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [2.2.2.2])
	by abc.luxsci.com (8.14.4/8.13.8) with ESMTP id r7JEfIkK030002
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT)
	for <someone@luxsci.net>; Mon, 19 Aug 2019 09:41:19 -0500

Proofpoint:

LuxSci uses an email filtering service, Proofpoint. Messages reach Proofpoint’s servers before being delivered to LuxSci. Here’s what their servers report about the email transmission:

Received: from unknown [65.54.190.216] (EHLO bay0-omc4-s14.bay0.hotmail.com)
	by dispatch1-us1.ppe-hosted.com.ppe-hosted.com
        (envelope-from <someone@hotmail.com>);
	Mon, 19 Aug 2019 08:41:18 -0600 (MDT)

Outlook:

And finally, here’s what we see from Oultook’s server.

Received: from BAY403-EAS373 ([65.54.190.199]) by bay0-omc4-s14.bay0.outlook.com
       with Microsoft SMTPSVC(6.0.3790.4675); 
       Mon, 19 Aug 2019 07:41:19 -0700

How to Use Received Message Headers to Tell if the Email is Encrypted

The message headers contain information that can help us determine if an email is encrypted. Here are a few helpful notes to help you decode the text:

  1. We said this above, but the message headers appear in reverse chronological order. The first one listed shows the last server that touched the message; the last one is the first server that touched it (typically the sending server).
  2. Each Received line documents what a server did and when.
  3. There are three sets of servers involved in this example: one machine at Hotmail, one machine at Proofpoint, where our Premium Email Filtering takes place, and some machines at LuxSci, where final acceptance of the message and subsequent delivery happened.

Presumably, the processing of email within each provider is secure. The place to be concerned about is the hand-offs between Hotmail and Proofpoint and between Proofpoint and LuxSci, as these are the big hops across the internet between providers.

In the line where LuxSci accepts the message from Proofpoint, we see:

(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT)

This section, typical of most email servers running “sendmail” with TLS support, indicates that the message was encrypted during transport with TLS using 256-bit AES encryption. (“Verify=not” means that LuxSci did not ask Proofpoint for a second SSL client certificate to verify itself, as that is not usually needed or required for SMTP TLS to work correctly). Also, “TLSv1/SSLv3” is a tag that means that “Some version of SSL or TLS was used;” it does not mean that it was SSL v3 or TLS v1.0. It could have been TLS v1.2 or TLS v1.3.

So, the hop between Proofpoint and LuxSci was locked down and secure. What about the hop between Hotmail and Proofpoint? The Proofpoint server’s Received line makes no note of security at all! This means that the email message was probably not encrypted during this step.

Hotmail either did not support opportunistic TLS encryption for outbound emails, or Proofpoint did not support receipt of messages over TLS, and thus, TLS could not be used. With additional context, you can know which server supports TLS and which does not.

In this case, we know that Proofpoint supports inbound TLS encryption. In fact, from another example message where LuxSci sent a message to Proofpoint, we see the Received line:

Received: from unknown [44.44.44.44] (EHLO wgh.luxsci.com)
	by dispatch1-us1.ppe-hosted.com.ppe-hosted.com
        (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
	with ESMTP id b-022.p01c11m003.ppe-hosted.com
        (envelope-from <from@domain.com>);
	Mon, 02 Feb 2009 19:28:27 -0700 (MST)

The red text makes it clear that the message was indeed encrypted. Based on the additional context, we can deduce that the Hotmail sending server did not securely transmit the email using TLS.

How To Tell if an Email is Encrypted With TLS

  1. When analyzing your message headers, consider the following items to determine if the email is encrypted:
    1. The receiving server will log what kind of encryption, if any, was used in receiving the message in the headers.
    2. Different email servers use different formats and syntax to display the encryption used. Look for keywords like “SSL,” “TLS,” and “Encryption,” which will signify this information.
    3. Not all servers will record the use of encryption. While LuxSci has always logged encryption use, not every email service provider does. It is possible to use TLS encryption and not log it. Sometimes, there is no way to tell from the headers if a message is encrypted if it is not logged.
    4. Messages passed between servers at the same provider do not necessarily need TLS encryption to be secure. For example, LuxSci has back-channel private network connections between many servers so that information can be securely passed between them without SMTP TLS. So, the lack of TLS usage between two servers does not mean the transmission between them was “insecure.” You may also see multiple received lines listing the same server: the server passes the message between different processes within itself. This communication also does not need to be TLS encrypted.
    5. If you are a LuxSci customer, you can view online email delivery reports to see if TLS was used for any particular message. We record the kind of encryption in the delivery reports, so it’s easy to see which emails were encrypted.

How can you Ensure Emails Are Securely Transmitted?

With some servers not recording TLS in message headers, how can you determine if a message was transmitted securely from sender to recipient?

To answer this question accurately, you must understand the properties, servers, and networks involved. It may be easy to determine that the message was transmitted securely if included in the header information. However, the absence of information does not necessarily mean the message was insecurely transmitted. You can only know this if you know what each system’s servers record.

In our example of a message from Hotmail to LuxSci, you need to know that:

  1. Proofpoint and LuxSci will always log the use of TLS in the headers. We can infer that the Hotmail to Proofpoint transmission was not secure as nothing was recorded there.
  2. The transmission of messages within LuxSci’s infrastructure is secure due to private back channel transmissions. So, even though there is no mention of TLS in every Received line after LuxSci accepts the message from Proofpoint (in this example), transferring the messages between servers in LuxSci is as secure as using TLS. Also, the same server can add multiple received lines as it talks to itself. Generally, these hand-offs on the same server will not use TLS, as there is no need. In the LuxSci example, we see this as “abc.luxsci.com” adds several headers.
  3. We don’t know anything about Hotmail’s email servers, so we don’t know how secure the initial transmissions within their network are. However, since we know they did not securely transmit the message to Proofpoint, we are not confident that the transmissions and processing within Hotmail (which may have gone unrecorded) were secure.

Was the email message sent and received using encryption?

We skipped steps 1 and 3 and focused on step 2 – the transmission between servers. Steps 1 and 3 are equally, if not more, necessary. Why? Because eavesdropping on the internet between ISPs is less of a problem than eavesdropping near the sender and recipient (i.e., in their workplace or local wireless hotspot). So, it’s essential to ensure messages are sent securely and received securely. This means:

  • Sending: Use SMTP over SSL or TLS when sending messages from an email client or use WebMail over a secure connection (HTTPS).
  • Receiving: Ensure your POP or IMAP connection is secured via SSL or TLS. If using WebMail to read your email, be sure it is over a secure connection (HTTPS).
  • WebMail: There is generally no record in the email headers to indicate if a message sent using WebMail was transmitted from the end-user to WebMail over a secure connection (SSL/HTTPS).

You can typically control one side and ensure it is secure; you can’t control the other without taking extra steps. So, what can you do to ensure your message is secure even if it might not be transmitted with encryption or if the recipient tries to access it insecurely?

You could use end-to-end email encryption (like PGP or S/MIME, which are included in SecureLine) or a secure web portal that doesn’t require the recipient to install or set up anything to get your secure email message. These methods meet HIPAA and other regulatory compliance requirements for secure data transmission and provide complete confidence that the message will be sent and received securely.

LuxSci’s SecureLine offers flexible encryption options, including TLS, secure web portal, PGP, and S/MIME. Its dynamic capabilities can determine what types of encryption the recipient’s server supports to ensure your emails are always sent securely. Contact our team today to learn more about how to secure your emails.