Yes this is correct. It works using betterbird with the same settings.

Thank you.

I tried these things. I can get a shell using the command you gave me.

Bute the second test withj openssl does not work within the container shell because of the missing openssl command.

But it worked directly on the NAS. i got

220 mxe83f.netcup.net ESMTP Postfix (Debian/GNU) as response from the server

Ja was genau benötigt du bei m365. Für den Officeteil gibts gute Alternativen von Libreoffice über bis hin zu Softmaker Office mit sehr guter Kompatibilität. Alles auch unter Linux.