This free online service analyzes the configuration of the inbound email servers for any domain with respect to the quality of their support for SMTP TLS.


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TLS, short for Transport Layer Security, is a protocol used for establishing a secure connection between two computers across the Internet. As an email provider we give our clients the best of security options, and TLS is a very important security tool. Our system gives our users the option to use TLS when connecting their email program (e.g, Outlook, Apple Mail, etc.) to our incoming and outgoing email servers for the purpose of encrypting the connection itself.

Read: SMTP TLS: All About Secure Email Delivery over TLS

Enforced use of SMTP TLS is one of several methods that LuxSci SecureLineTM email encryption can use to ensure secure email delivery. See: How SecureLineTM Works. In particular, LuxSci SecureLineTM allows you to leverage TLS for secure email delivery, if you choose, via:

  • Dynamically determining what recipients support TLS, so you do not have to pre-configure anything.
  • Automatic fall-back to other email encryption modes when TLS is not available, so you don't have to configure anything.
  • Allowing you to optionally specify which domains or recipients are OK or not OK for TLS-Only email delivery.
  • Allowing you to optionally NOT deliver email to people who do not support TLS, instead of using other encryption methods (good for email marketing in a compliance context).
  • Access to an API where you can check domains for their TLS support before you ever send email messages.
  • Access to an API for sending secure email messages, in case you prefer to not use SMTP directly.

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