Emails not working after upgrade: certificate verify failed

We use our own SMTP server for sending emails. It has been working fine with Discourse for the last few years.

We recently updated Discourse from 2.8 (beta) to 2.9 (beta). We are unable to send the emails now.

Output of ./discourse-doctor:

==================== MAIL TEST ====================
For a robust test, get an address from
Or just send a test message to yourself.
Email address for mail test? ('n' to skip) [REDACTED]: REDACTED
Sending mail to REDACTED. . .
Testing sending to REDACTED using, username:REDACTED with login auth.
======================================== ERROR ========================================
                                    UNEXPECTED ERROR

SSL_connect returned=1 errno=0 state=error: certificate verify failed (self signed certificate)

====================================== SOLUTION =======================================
This is not a common error. No recommended solution exists!

Please report the exact error message above to
(And a solution, if you find one!)

Earlier we got another error: certificate verify failed (EE certificate key too weak). We regenerated the OpenSSL certificates on our email server. Now we are getting this error.

This same server with the same settings was working fine for the last couple of years. Something in v2.9 (beta) has made the SMTP SSL connect stricter.

How can I navigate this? Any leads will be very helpful.

1 Like

There’s some discussion and advice about a similar error in this recent topic that may be helpful :crossed_fingers: