William Park via Talk wrote on 2026-01-02 00:43:
I saw "found certificate exception" warning on POP. No warning on IMAP account.
That's interesting! Seems like a misconfigured server. Who's the provider, can you say? It seems like a stanza in, say, /etc/dovecot/conf.d/10-ssl.conf, has an incorrect / expired cert for the POP3 entry. I bet POP3 would work if you manually pointed Thunderbird at imap.yourISP.com instead of pop3.yourISP.com - valid certificate presented, and your choice of protocol can be used. Just thinkin' out loud...
And, Thunderbird recommends IMAP. They know more about "email" than I do, so go with the flow. Not a bad choice, for sure.
(And... TB just added about 20 blank lines as quotes at the end of this message. Fortunately the cursor didn't randomly jump to the end mid-sentence, grrrr.)