Hey @davidep thank you for the quick solution.
I tested with gmail.com and web.de
Gmail is working!
web.de throws the following error:
Dec 10 23:22:46 asterix default/smtp[19439]: warning: SASL authentication failure: No worthy mechs found
Dec 10 23:22:46 asterix default/smtp[19439]: 1E6A9A807E9: SASL authentication failed; cannot authenticate to server smtp.web.de[213.165.67.108]: no mechanism available
Dec 10 23:22:46 asterix default/smtp[19439]: warning: SASL authentication failure: No worthy mechs found
Dec 10 23:22:46 asterix default/smtp[19439]: 1E6A9A807E9: to=abc@nothing.com, relay=smtp.web.de[213.165.67.124]:25, delay=0.52, delays=0.3/0.01/0.2/0, dsn=4.7.0, status=deferred (SASL authentication failed; cannot authenticate to server smtp.web.de[213.165.67.124]: no mechanism available)
telnet to smtp.web.de 587 is working.
Do you have an idea whats wrong?