Our mailserver is a Ubuntu Server box with a Postfix/Dovecot combination. We enabled starttls with a correct certificate and everything is working ok.
A lot of our users are using Thunderbird for retrieving mail with IMAP. Thunderbird tries to guess the configuration of our server (or autodetect it), but that always fails, resulting in that our users need to give the settings manually.
What are the steps we should take to 'help' thunderbird and enabling auto-configuration?
Thunderbird autoconfig is described here
You may want to use a tool like automx though which supports auto-configs for other mail clients as well.
Basically You have to serve a simple configuration XML file on the
autoconfig.example.com/mail/config-v1.1.xmladdress, described on this page:https://developer.mozilla.org/en-US/docs/Mozilla/Thunderbird/Autoconfiguration/FileFormat/HowTo