Have some of you configured your lemmy server to send e-mails using starttls?

So I have an issue with my smtp settings, I can't get my Lemmy instance to send e-mails using my SMTP server using starttls and wondered if some of you have managed to do so?

If so I would like to compare client and server settings to understand what is going wrong with my setup.

In the meantime I have opened issues at lemmy and lettre repo but I'm trying to get help anywhere I can :)