High VolumeTM Secure Email Sending


High VolumeTM

  • High-quantity, high-quality outbound email
  • Thousands to millions of messages/month
  • Marketing or transactional messages
  • Dedicated servers, clusters, & environments
  • Dedicated reputation & high availability
  • Apply encryption, DLP, etc.

HIPAA Compliance

  • Actually include ePHI in your email messages
  • Reduce your risk: encrypt everything by default
  • Highly-configurable & flexible email encryption
  • Access controls, login audit trails, and more
  • Business Associate Agreement

SecureLineTM Email Encryption

  • Send secure email to anyone
  • Adaptive Encryption: TLS, Portal pickup, PGP & S/MIME support
  • Opt-in, Opt-out, & DLP encryption
  • Use SMTP or our REST API
  • Discover: SecureLineTM


  • TLS = Security + Usability + Compliance
  • Dynamic: Determine TLS support "on the fly"
  • Exclusive: Option to only send email to those supporting TLS
  • No TLS pre-configuration needed
  • No accidentally insecure messages sent

Spotlight Mailer

  • All-in-one web-based email marketing platform
  • Email campaigns & message templates
  • Mailing list management
  • Discover: Spotlight Mailer

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Custom Enterprise Solutions

Custom large-scale solutions

Custom solutions can be tailored for very high volumes of sending, very high throughput, very high security, and business continuity. They can include:

  • Redundant high-availability dedicated hardware firewalls
  • Redundant high-availability dedicated load balancers
  • Network-based intrusion detection systems
  • DDOS Protection up to 100 Gbps
  • Redundant, load-balanced outbound email sending servers
  • Dedicated databases and management web interfaces
  • Physical system isolation and capacity scaling
  • An additional disaster recovery footprint in a different data center

If a custom solution might be right for you, talk to a LuxSci Expert.

LuxSci has exceeded our expectations in every way. Setting up the account was very simple. The different rates for the amount of mail you wish to send makes it easy to pick the plan that best suits your needs at a affordable price. Customer Service has been attentive when needed. Most importantly the mailing has gone very smoothly and without interruption. I am a very happy customer and would highly recommend LuxSci to anyone looking to improve your mailing needs. Thank you LuxSci."

Dax Kirks . Best Buy Windows and Siding

eBook: HIPAA-compliant Bulk Emailing Basics

A technical guide to bulk emailing

Book 3 in the LuxSci Internet Security Series.

Created by Erik Kangas, PhD

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Features: High Volume Secure and Basic

LuxSci's High Volume Email Sending Service includes two service options, "Basic" and "Secure." High Volume "Basic" is a stand-alone SMTP-only service that is available by special order only for customers with large-scale SMTP relaying needs.

High Volume "Secure" Sending provides full featured secure email sending with High Volume sending limits. Both options have the same set of capabilities and reporting options. The High Volume Secure Sending service provides more extensive security options, such as HIPAA compliance, outbound email encryption, email archival, and additional administrative features and controls.

Dedicated Servers

Feature Basic Secure
Dedicated IP Address
SLA (Service Level Agreement) includes 100% network and infrastructure guarantee
Separation from other customers ensures you aren't affected by
their usage patterns or reputation
Branded Email Headers [Optional]

Dedicated server customers can choose to have the headers of all outbound messages "branded" with their domain name and organization and with all references to LuxSci and "High Volume" removed:

  • Hostname: the server hostname that appears in the mail headers will be your server name (e.g.. "" instead of ours (e.g. "")
  • Reverse DNS: Anyone looking up the hostname of your server from its IP address will get your custom hostname back, and not a LuxSci server name.
  • Abuse Email: Include your own "Abuse Reporting" email address in the headers instead of ours (though the emails will still be routed to us).
  • Powered by: Include your own "Powered by" header line in place of our "LuxSci High Volume" header line.

Email Delivery

Feature Basic Secure
Use Your Own From Addresses

You can only send messages from an email address in a domain that you own. Addresses from "free email services (e.g., hotmail)" are prohibited.

  • Basic Service users can send from multiple "from addresses" or domains that have been approved by LuxSci Support.
  • Secure Service users can send from any email address in a domain that they own or manage, the approval step is not required.
Reverse DNS (rDNS) records
Reverse DNS records point the IP address of your email server to the server's domain name. This information reduces the risk of the receiving server viewing the email as spam.
Alternate SMTP Ports
Alternate ports for SMTP access: 80, 465, 587, 2025, 6025, and 6465. If firewalls or ISPs attempt to block your messages, sending your email via these alternate ports helps ensure that your messages are delivered.
DKIM - Sign outbound messages
DKIM allows receiving email servers to feel more confident that the email originated from the listed domain, increasing the deliverability of your message.
SPF and Sender ID authentication information is used by receiving email servers that are checking for spam. The existence of this information reduces the chance that your email is blocked.
Anonymous SMTP - IP Masking
Anonymous SMTP hides the IP address of the computer or server that is sending the message. This feature increases deliverability when you are sending from an ISP or location that is blocked or has a poor reputation.
IP Monitoring
LuxSci checks its server IP addresses to make sure that they are not on blacklist databases and to immediately alert us of any blacklisting issues so that they can be immediately addressed.
Graylist and blacklist resolution
LuxSci works to resolve problems that may have resulted in your IP being gray or blacklisted.


Feature Basic Secure
Messages Sent
This online or emailed report lists successfully sent messages. It can be downloaded, sorted, and searched
Tracking and Deliverability
This online or emailed report lists the delivery status of every message sent to every recipient. It can be downloaded, sorted, and searched. For messages that were not successfully delivered, the delivery issue is listed. Summary reports are available on a daily and monthly basis.
Tracking Soft and Hard Bounces
Automatic tracking of delivery success and failure. Automatic processing of post-delivery bounce messages and updating of message delivery status. Automatic differentiation between "soft" and "hard" failure messages.
Email Delivery Status Digests
This emailed report lists all email delivery status updates for all messages sent to a specified email address or list. It is useful for automating processes and for automatically informing you of issues. It is delivered to you automatically on a frequency that you select (e.g., weekly). The report is sent to your email in HTML and also includes an Excel file for easy analysis.
Email Delivery Failure Reports
This report lists all email delivery failures and includes the reason why the delivery failed. The report is sent to your email in HTML and also includes an Excel file for easy analysis. It can be used, for example, to discover misspelled addresses and to remove non-working addresses.
Feedback Loops (SPAM notifications) with Major ISPs
LuxSci works with major ISPs to quickly detect spamming and other issues and to help keep our servers off black lists. LuxSci users can see SPAM complaints by logging into the system. Users can also have their SPAM complaints automatically sent to their email. Complaining recipients can then be easily removed from their mailing lists.
Auto-block future email to complainers (optional)
For recipients that complain that your messages are unwanted/spam-like, and where those complaints come back through the standard feedback looks from Major ISPs, LuxSci can automatically add the problem recipient email addresses to your domain-wide recipient block list. Thence forward, all email sent to those same addresses by anyone in the same domain will be automatically blocked (and logged).

Its your job to make sure that your mailing lists are opt-in and clean and to remove the addresses of everyone who complains in any way. Auto-blocking of complainers is a safety net for you -- even if you make a mistake and send to a complainer ... we will be sure the message is stopped before it gets to them.

This feature must be enabled in your domain's outbound email settings page.

Bounce Processing
Open Tracking
URL Click Tracking
Custom Header Tracking & Reporting
Track the values of up to 3 custom email headers added by your sending email systemm. Use these when searching for messages and generating reports. See these down downloading reports.
API: Access these reports via our REST API
  • Messages sent
  • Delivery status
  • Feed back loop notices
  • SMTP login failures and message sending rejections
  • Email ppens
  • Email URL clicks


    Feature Basic Secure
    SMTP username & password authentication
    SSL/TLS connections to SMTP
    LuxSci provides the following protocols for sending your emails: insecure SMTP, SMTP over TLS, or SMTP over SSL. Optionally, configure your account to require the use of SSL or TLS.
    Opportunistic TLS delivery to TLS capable mail servers
    LuxSci automatically uses TLS to deliver email securely to any recipient email server that supports SMTP TLS.
    Encrypted message delivery to any recipient
    Secure High Volume allows you to send secure, encrypted, messages to every recipient, no matter what email provider the recipient uses.
    HIPAA compliance available
    Secure High Volume can be used when sending sensitive email messages and ePHI, so that your email sending can be HIPAA compliant.
    Recipient restrictions
    Use allow and deny lists to control to whom or to what domains messages can be sent. Send copies of all outbound email messages to an email address of your choice.
    Email capturing
    Direct copies of all sent messages to another email address of your choice.
    Email content monitoring/DLP
    Scan all outbound email for specific content (keywords, phrases, or regular expressions). Matching messages can be denied, sent to an auditor, or auto-encrypted using SecureLineTM.

    Message Options

    Feature Basic Secure
    Up to 200 MB total encoded message size
    A limit of 200 MB in encoded message size allows you to send emails with sizable attachments.
    Up to 1,000 recipients per message
    Choose the number of recipients from a single individual up to 1000.
    Any format (HTML, plain-text, multi-part, attachments)
    This option helps ensure that your email can be seen by all recipients, no matter what kind of email viewing program they use.
    Auto-add Taglines/Disclaimers
    Save time by having the software automatically add taglines/disclaimers to your outgoing email in either plain text or HTML format.
    Archive all outbound email


    Feature Basic Secure
    Private Labeling Available
    Private labeling is an additional service offered to high volume customers. Private labeling enables your customer to see only references to your company, not LuxSci, on your user interface and sent emails.
    Account-wide monthly recipient limit
    For each account, choose the monthly recipient limit. A recipient is one email sent to one person.
    Configure optional per-user recipient and/or bandwidth limits
    Allocate your resources effectively by establishing user-specific recipient and/or bandwidth limits.
    Use your own email addresses for authentication
    This option allows you to use a familiar username or a branded username for login.
    Usage notices sent automatically at customizeable thresholds
    Track your SMTP usage with reports that are automatically sent to the sender or account administrator when usage reaches a specified limit.
    Easy and instant recipient volume upgrades
    As your email usage expands, LuxSci supports this growth with the upgrades you need.
    Receive & check inbound email
    Get a fully-functional email hosting account with SecureLineTM, IMAP, POP, and WebMail access to your inbound email. This is very useful if you need to process replies and bounces, or need to managed secure replies to encrypted outbound email messages.
    WebMail access for sending and receiving email messages. Includes an WebAide App collaboration tools.
    WebAidesTM: Address books, calendars, tasks, file storage, etc.
    Inbound email filtering
    Upgrade/Add Related Services
    Depending on what you need, this kind of account can be upgraded to add such things as Premium inbound email spam and virus filtering, inbound and outbound email archival, domain registration and DNS services, more disk space, private labeling, web hosting and more.

    FAQs: Perhaps you were wondering...?

    While LuxSci does not offer pay-as-you-go sending, High Volume Email Sending is available as an add-on to shared secure email services as long as your sending needs are modest (less than 100,000 messages/month).

    As many as you like! LuxSci does not limit the number of legitimate subscribers or how you segment your lists. We base our plans on the number of recipients you send messages to each month.

    A recipient is an email address a message is sent to. It's also the unit we use to measure your email sending. One message to one person is one recipient, two messages to the same 10 people comprise 20 recipients, 1000 messages to one person each equals 1000 recipients.

    LuxSci does not limit the number of messages you can send at once. You can send a single message or email blasts that go to thousands or millions of recipients. Your plan determines the maximum number of recipients you can send to per month.

    Yes, LuxSci provides the option of purchasing Spotlight Mailer, a web-based email marketing and campaign management solution. You also have the option of continuing to use your current email software.

    Yes. LuxSci SecureLineTM has a special feature called TLS Exclusive. When you enable this, LuxSci will dynamically use Forced TLS to deliver your messages securely to everyone who can support TLS and will drop messages to those who don't (with appropriate notes in our delivery tracking system). If you have low priority messages (e.g., email marketing messages) which still need to be secure (e.g., in healthcare), "TLS Exclusive" high volume sending is a perfect fit.

    The number of sustained concurrent connections you can make at once depends on your service level. Large dedicated servers or clusters would be recommended for cases requiring high levels of concurrency. See Sending Rates.

    While any email provider can and does get blocked on occasion, LuxSci takes stringent measures to keep this from happening. LuxSci has very strict acceptable use policies and manually checks every new customer to keep spammers out. LuxSci's monitoring system works to detect any improper use before it becomes a problem. As a result, problems are rare. If a problem does occur, LuxSci's staff have the training to resolve the issue ASAP. Also, when you have a dedicated server (and thus a dedicated IP address), your IP address reputation reflects only your own sending history.

    No, you do not need to change your email hosting service to LuxSci. You can easily configure your sending programs to send your emails through LuxSci's email sending service without affecting your existing email solution.

    LuxSci provides the option of sending email via a dedicated server. The type of server used depends on your high volume plan. Your dedicated server may or may not use IP addresses recently used by other customers. So, they may or may not be "pre-warmed." We recommend warming up your new server yourself for best delivery results. See also: Warm up your IP automatically.

    While neither LuxSci nor anyone else can ensure that every message is delivered to every Inbox, our excellent reputation and stringent security measures maximize the chances that your email messages will go to the intended recipients. LuxSci will advise you on how to construct your messages and maintain your lists and campaigns for the best result. See Key Ingredients for Good Deliverability.

    Yes! LuxSci provides reports of messages sent, delivery status as well as complaints of spam such as feedback loop complaints. Note that Spotlight Mailer automatically maintains your mailing lists as bounces occur or recipients subscribe or unsubscribe.

    Other questions? Call Sales

    How Fast Can You Send Email?

    For the best throughput, choose the most powerful server or cluster that you can afford. When delivery speed (i.e., messages/hour) is a factor, a more powerful server will receive, process, and deliver deliver your messages faster. If budget is limited, a less powerful server may still get your message out in an acceptable time frame.

    To optimize your throughput, ask our experts about custom cluster solutions.

    Dedicated Server Size

    1 CPU 2 CPU 4 CPU 8 CPU
    Maximum msgs/hr 20,000 40,000 80,000 160,000
    Maximum msgs/day 450,000 900,000 1,800,000 3,600,000
    Recommended #
    sustained connections
    1 2 4 8

    For increased capacity, high burst rates, or to account for other factors (see below) like large messages, lack of pipelining, etc., we recommend choosing a larger server or a load-balanced multi-server clusters.

    What do these terms mean?

    Sending Rate

    The maximum sustained rate at which you can deliver email to the server, have it processed, and have it delivered to the recipient's mail servers depends on many factors. These include:

    The speed by which you can deliver message to your server:

    1. Email sending program used
    2. Proper use of concurrent connections
    3. Network speed between the sending program and LuxSci
    4. Server power (CPU cores, memory, and disk speed)
    5. Use of SMTP pipelining
    6. Message size

    The speed by which the messages can be processed (i.e., encrypted, tracked, etc.):

    1. How much your sending email program is pushing new messages to the server
    2. Server power (CPU cores, memory, and disk speed)
    3. Message size
    4. Rate limiting (i.e., for IP warm up)

    The speed by which the messages can be delivered to recipients

    1. How much your sending email program is pushing new messages to the server
    2. Server power (CPU cores, memory, and disk speed)
    3. Message size
    4. Recipient server and DNS performance
    5. Blacklisting and greylisting

    These factors determine how fast your can have a quantity of messages delivered to their recipients. Some of these factors are under your control and some of them are not.

    Maximum msgs/hr The "maximum sending rate" (msgs/hr) is the upper bound rate that you can achieve through the service. It assumes optimal sending conditions for high volume encrypted email: very small (5 KB) messages, all to the same domain, sent over a fast network using SMTP Pipelining, and encrypted using TLS. Under these conditions, there is no blacklisting, gray listing, or DNS slowness, there are no problems with some recipient email servers, and we choose an optimal sustained number of concurrent sending connections to the server.

    Expected Rate: Under normal sending conditions, your delivery throughput may be below the maximum sending rate.

    Maximum msgs/day This is an estimate of the maximum number of messages that your server could process and deliver over 24 hours of sustained sending at approximately the maximum hourly rate.

    Sustained vs Burst Rate

    For some customers, the speed of sending is very important. There are two significant modes of sending:

    Sustained Rate

    Making one or more connections to your server and then sending at a consistent rate for a long period of time. E.g. 20,000 messages/hour for minutes or hours. Sustained rates are relevant when sending an email marketing blast to a large subscriber list or when offloading a large number of messages from an external application through your sending server.

    Burst Rate

    A "burst" refers to sending a bunch of messages in a very short time; e.g. 25 or 50 messages within a second or two. Burst differs from "sustained" in that "bursts" are short duration events and when you are not "bursting" you are sending relatively few messages here and there ... infrequent sending. Bursting is relevant for transactional email messages when you are sending them "as needed" but require the ability to send many at once should that need arise, as it will.

    Sending speed is important for customers who need to send large mailings at a sustained rate. Understanding sending speed helps you determine how long it will take to send that blast to 100,000 or 1 million subscribers.

    Factors Affecting your Sustained Sending Rate

    There is a theoretical maximum number of messages/hour that any server can manage. How fast you can actually send is affected by a number of factors.

    1. Server Power

    More powerful servers can handle more concurrent connections, process more messages at once, deliver more messages at once, and thus give you higher sending rates. The number of CPU cores is the primary factor governing performance; however, memory and disk speed are also important.

    2. Email Sending Program

    Different email marketing/sending programs have different capacities for how efficiently they can send high volumes of email. Simply switching from one program to another can increase your throughput significantly.

    3. SMTP Pipelining

    Use an email marketing program that supports SMTP Pipelining. With this feature, the program opens a single authenticated connection to the server and sends multiple messages in succession over that connection. This is significantly faster than opening a new connection and authenticating again for every single message to be sent.

    4. Concurrent Connections

    If your sending program can open multiple connections to our SMTP servers at the same time and send multiple messages at once, then you can delivery messages to our servers more quickly. Depending on how powerful your server is and how slow your network connections are, you can use more and more concurrent connections to achieve higher and higher sending rates. Combined with SMTP Pipelining, an appropriate number of concurrent connections goes a long way to maximizing your throughput potential.

    Under most circumstances, sending programs can deliver messages to our servers much more quickly than the servers can process those messages (i.e., encrypt them, track them, log them, etc.) and then deliver them to the recipients' mail servers.

    The recommended maximum number of concurrent connections to use for sustained email sending is given in the table, above. It is important to note that while exceeding that recommended value will get your email to your server faster, sustained sending at that rate will overtax the server and cause the overall rate of processing and delivery of your messages to your recipients to slow down. Stick to the recommended number of concurrent connections for sustained sending.

    5. Network Speed

    Your messages must be transmitted from your email sending program to our servers. The speed of your network, any packet loss, and the distance between your sending computer and our servers can significantly impact the maximum rate that you can send messages.

    6. Message Size

    Like network speed, the larger your messages are, the more time it will take to transmit them from your email sending program to our servers. For example, on a fast network, increasing message size from 5KB to 1MB decreased throughput by 50%. The actual impact of size will depend greatly on your network speed and other factors.

    7. Recipient Email Server and DNS Speed

    In order for our servers to deliver messages to your recipients, the servers have to (a) look up where to deliver the messages to (DNS), and (b) talk to those servers to deliver the messages to them. If the DNS lookup as slow or the recipients are in domains that do not exist, this step can take a while. If the recipient's email servers are overloaded, on a slow network, or are having other issues, then the delivery phase can be slow.

    Delivering many messages to recipients with these issues can slow down your entire sending process... as other messages have to wait for the slower ones to be sent.

    8. Blacklisting and Greylisting

    If your email content or sending patterns have gotten your server blacklisted or greylisted, then delivering email messages to recipient servers that are now blocking you or deferring you can slow down your delivery rates.

    This can also cause a backlog of messages that are waiting to be accepted by these recipient servers. The need to Retry the backlog slows the process of delivering all other messages (though it does not block their delivery).

    9. Recipients per message

    Most email marketing and transactional email messages are sent individually to each recipient. This allows easier tracking of opens, views, etc. However, if you send each message to many recipients (e.g., 100s of recipients), then your sending program has significantly fewer messages to deliver to our servers. The delivery of your messages to our servers can happen 10s or 100s of times faster than if you sent in the usual one recipient/message pattern.

    Additionally, if each message contains only recipients in a specific domain, then actual delivery to these recipients can be expedited by this efficiency. E.g. If you are sending to 500 AOL users, instead of sending 500 individual messages, send one message with all 500 AOL users listed as "BCC" recipients. Delivery can be almost 500 times faster.

    10. SecureLine Email Encryption

    In the example sending rates, we assumed that all messages would be sent using SecureLine TLS. If PGP, S/MIME, or Escrow are used, that can also impact email processing speed.

    11. Outbound Email Processing

    If you are using other email processing features that come with High Volume Secure Sending (e.g. content scanning, recipient restrictions, size restrictions,etc.), this processing may affect your maximum sending rate.

    12. Throttling

    LuxSci has features that can be used to rate limit the processing of outbound email. This is usually used when "warming up" IP addresses to assist senders in sending slowly and establishing their IP address reputation.

    This rate limiting is on, your maximum sending rate will be capped by this process.

    See also:

    Acceptable Use Policy

    Zero tolerance policy for sending of spam and unsolicited commercial email

    The Acceptable Use Policy is very explicit about what you can and cannot do with the High Volume Secure Sending service. Highlights include:

    From Addresses

    1. A user can send from any "From" or "Reply To" addresses without the need for prior approval (except for those addresses excluded by the next item). Note that our regular Acceptable Use Policy still applies; sending messages from addresses that you don't own or manage is an AUP violation and subjects your account to possible termination without notice.

    2. A "From" address cannot be that of any email service provider (free or not). That is, no sending bulk messages from "AOL," "Gmail," "Hotmail," "Yahoo!," your college email address, etc. In general, you should only send from a valid address in a domain you own.

    Abuse Tracking

    Headers are added to each message sent so that it can trace back to the sender should anyone report abuse complaints. Headers also include information to notify recipients to contact LuxSci to report abuse.

    Message Content

    1. LuxSci Support reserves the right to inspect (in a way compliant with our privacy policy and HIPAA BAA, if appropriate) any message sent through the High Volume messaging service to ensure that every message meets our terms of service.
    2. All messages must indicate in the body of the email why the recipient is getting the message and provide a viable means by which the recipient can opt out of future mailings.

    Other Restrictions

    1. The sender must promptly comply with any and all opt-out requests.
    2. Spam, unsolicited commercial email, email sent to purchased email lists, any bulk mailing to anyone not explicitly expecting your messages are not permissible.
    3. The terms of service are strict; LuxSci will not tolerate abuse. LuxSci may suspend service without notice if it receives any complaints and until the parties resolve the issue.

    Prohibited Content and Industries

    High Volume services may not be used for the sending of email:

    1. Offering to sell illegal goods or services
    2. That violates the CAN-SPAM Laws
    3. That is marketing or commercial email being sent to recipients without their permission
    4. That contains pornography or other sexually explicit material

    Furthermore, High Volume services are not to be used for the sending of email for any of the following industries:

    1. Work from Home, Make Money Online, and Lead Generation opportunities
    2. Multi-level and Affiliate marketing
    3. Get Out of Debt and Credit Repair opportunities
    4. Gambling products or services
    5. Adult References or Adult Novelty Items
    6. Escort services or Dating services (excluding legitimate Dating sites)
    7. Loans or Mortgages
    8. Offers to buy pharmaceutical products (unless you are directly employed by a major pharmaceutical company)
    9. Stock Market content, Day Trading Tips, and other Online Trading content
    10. List Rental services and List Brokers
    11. Vitamin, Herbal, and Nutritional supplements (unless you are employed directly by a major company producing these products)

    Customers wishing to send this type of content should consider setting up their own mail servers, as most legitimate email marketing companies will not be able to help you.