Thunderbird does not connect to Dovecot. Webmail is ok.

Posted on April 20, 2015

I set up my mail server with Postfix (MTA) and Dovecot (IMAP, POP3). When I tested my installation with an open source webmail interface everthing has been working well: login with username and password, receive mails (port 993, ssl/tls) and send mails (port 587, starttls). Today I started testing local clients beginning with Thunderbird. Here I get an error message like this: Click Me.

In Dovecot I have already changed

ssl_protocols = !SSLv3 !SSLv2
to
ssl_protocols = TLSv1.2 TLSv1.1 TLSv1 !SSLv3 !SSLv2

Moreover I tried to deactivate the OCSP certificate validation in Thunderbird (Settings > Enhanced > Certificates > Validation)

But the issue keeps existing :( Anyone here to help me please?

This textbox defaults to using Markdown to format your answer.

You can type !ref in this text area to quickly search our full set of tutorials, documentation & marketplace offerings and insert the link!

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

Andrew SB

June 20, 2016

From the question linked here and other conversation on the internet, it seems as if there is a bug in Thunderbird. It looks like Thunderbird fails to prompt the user to accept a self-signed certificate.

One work around seems to be importing the certificate manually through Thunderbird’s certificate setting menu. You can find it through Preferences > Advanced > Certificates > View Certificates:

Import cert