https://bugs.kde.org/show_bug.cgi?id=420474
--- Comment #3 from Damian <m...@dsthode.info> --- Hi Panagiotis, sorry for the late response but I didn't see your reply. I've found the root of the problem. I configured the outgoing mail server to try and send a message but it failed again with the same symptoms in Wireshark, only that this time I had an error pop-up with the following error code from OpenSSL: "141A318A:SSL routines:tls_process_ske_dhe:dh key too small". I turned to Google and the first answer was [1] which explained that on 20.04 the minimum security level on OpenSSL was raised, thus the error message. I followed the suggestions in the answer and now I'm able to send and receive, so it's not really a problem with KMail, but with the default configuration of the OpenSSL library in Ubuntu 20.04. 1: https://askubuntu.com/questions/1233186/ubuntu-20-04-how-to-set-lower-ssl-security-level -- You are receiving this mail because: You are the assignee for the bug.