Thunderbird email client error
Thunderbird email client error while downloading emails.
Configured MS Office 365 F3 account with POP3/SMTP protocol.
Error is: RETR command did not succeed. error retrieving the message. Server unavailable 21
Unable to download emails after the error.
The error is randomly happening for many users. At least 100 users are getting affected out of 1000 thunderbird users with Office 365 F3 plan configured with POP3/SMTP.
Alla svar (1)
Do you have more than one user auto deleting mail on fetch using POP3, sharing a pop3 account.
That would cause the error big time. Users can not share a POP mail account and delete messages from the server. These errors are what occurs, especially if someone deletes the mail after the server presents the list of available mail on the initial connection.