On 2017-02-17 (09:58 MST), Bastian Sebode <b.seb...@linet-services.de> wrote: > > Weirdly my friend uses the same Dovecot Version with Let's Encrypt on > his Server and it works with Thunderbird without any flaws. Mine fails > the same way in his Thunderbird and also in a fresh installation.
Well, at least you’ve narrowed the fault down to Thrunderbird. Are you using TB through a proxy? Do you have a corporate LAN or an anti-virus that is behaving as a man-in-the-middle (Anything that claims to protect your web-browsing)? Have you tried from a different connection? Maybe on a different machine with “identical” settings? Usually errors like these indicate you are not getting the secured connection you think you are. -- Apple broke AppleScripting signatures in Mail.app, so no random signatures.
