This website is a box of tools that lets you look at all the moving parts of standard Internet email, and at all the newer technologies including SPF, DKIM, MTA-STS, DMARC, DNSSEC, DANE, …

TestReceiver never actually sends an email, it just gets as close as possible, learning as much about the remote system as it can. Because CheckTLS focuses on security, TestReceiver tries …

Check that each one offers the version (s) of TLS (SSL) that you want, and only those versions. Use the SSL Version option in //email/testTo: to test both that the versions you want do work, …

Your email was sent, however it was NOT SENT SECURELY using TLS. See the //email/testFrom: Full Documentation for what the result email looks like if you select Extra …

Email Test ReceiverTest Results (test took 1 sec, scroll up to re-run)

It was designed to test if email can be received securely, but because it continues testing even if TLS fails, it can also show the inner workings of non-TLS email servers.

To test if your Sender has TLS enabled, use the CheckTLS //email/testFrom: ("TestSender") test to see if your email system will use TLS to send an email. Follow the instructions to tell …

To test Mandatory TLS, you need an email system that does not work right: one where encryption fails, so you can be sure your "have to have" TLS stops the email message from sending or …

We do have clients who, after understanding the question better, come back to using the CheckTLS (Confidence Factor ℠) to decide the "TLS version". For only allowing TLS1.2 and …

When you send an email to the special address listed below, //email/testMandatoryFrom: makes sure that Mandatory TLS is working. It does not invite your sender to use TLS and will not …