After install Ubuntu 18.04 everything worked OK for a while but some (unknown) update later killed incoming POP3 email, although outgoing is OK. ISP settings are correct and email works on all of my non-Ubuntu devices. Delete account and configure IMAP is no help.
Reformat drive, reinstall Ubuntu 16-something, email OK. Upgrade to 18.04, email still OK. But after various updates, POP3 stopped working.
Email is Thunderbird (60.6.1), but another email app exhibits same problem.
Anyone experience this?