[Users] Endless timeout then suddenly anything ok

[Michael]

Hello, here's another question about weird things happening :D

Whenever i POP my mailbox from posteo.de for the first time after boot, claws is waiting for reply like forever and it ends up with timeout, no matter how i set the limit. When i get the timeout popup, i click OK then POP again and this time, mails download immediately.

This was never happening a few months ago, it's rather new.

The account settings are  "Use Start-TLS" and POP - Protocol "Autoconfigure". Anything else is default.

On the server side, they have some special security / encryption stuff but it's all disabled for that mailbox.

They also have “Certification Authority Authorization (CAA)” and “HTTP Public Key Pinning (HPKP)” but i don't see how this should be related. There is no issue with certificates since long now.

Any ideas how i can 'debug' this incident ?