This was originally related to network issues which I hoped to get solved by upgrading the system (zypper -v dup) but did not. Solved by changing network manager.
But, apparently fetchmail is broken now. Fetchmail gives following errors in log:
fetchmail: getaddrinfo("imap.gmx.com","imaps") error: Name or service not known
fetchmail: IMAP connection to imap.gmx.com failed: Success
fetchmail: Query status=2 (SOCKET)
Same error is repeated for every mailbox.
Anyone else with the same issue?