User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Tried sending a mail

Actual results:

A popup window came up:

Sending of the message failed.
Peer’s Certificate issuer is not recognized.
The configuration related to xxx must be corrected.

Expected results:

It should have sent mail OR point to what exactly needs to be fixed as the xxx cert does not appear in the Certificate Manager so I have no clue what and how to fix.

Evolution works just fine with the exact same settings. The smtp is configured on port 587, startls, plain password.

Self signed certificate? If so, bug 1665577.

yes it is self signed, 1665577 seems a good place for it