AT&T (POP3) Settings
I have an AT&T account and for some reason or another, Thunderbird isn't recognizing the user-name and/or password and according to AT&T' s own website, their POP3 settings are:
Account Type - Select IMAP or POP3. • Incoming mail server - Enter imap.mail.att.net (IMAP) or inbound.att.net (POP3). • Outgoing mail server - Enter smtp.mail.att.net (IMAP) or outbound.att.net (POP3)
Incoming server - Enter 993 (IMAP) or 995 (POP3). • Use the following type of encrypted connection - Choose SSL. • Outgoing server - Enter 465 (IMAP and POP3). • Use the following type of encrypted connection - Choose SSL.
And all true settings were true, but Thunderbird isn't ( wasn't ) recognizing the settings...
ప్రత్యుత్తరాలన్నీ (1)
Those settings should work if you use a secure mail key, generated on the AT&T site, in place of the account password. Remove the passwords from Saved Passwords in Preferences, restart TB, enter the key when asked for a password.
https://www.att.com/support/article/dsl-high-speed/KM1010523/