Why mail retrieval fails?
Why do I sporadically get "The POP3 mail server (pop.att.yahoo.com) does not support UIDL or XTND XLST" and it goes away after restarting Thunderbird?
Wšykne wótegrona (1)
It's a problem that seems to appear with Yahoo POP accounts:
If you were to switch to IMAP access, the settings would be: incoming: imap.mail.yahoo.com on port 993, outgoing: smtp.mail.yahoo.com on port 465; SSL/TLS, authentication = OAuth2, User Name = email address.
https://support.mozilla.org/en-US/questions/1288812
http://kb.mozillazine.org/Convert_a_POP_account_to_a_IMAP_account