I run a dual boot system with Fedora 40 with Thunderbird installed via DNF and Windows 11 Professional with Thunderbird installed from the Mozilla download site. I have had a Gmail account configured on both sides for some time. Recently I have been seeing very slow (2-3 minutes) outgoing sends from the Gmail account on the Fedora side ( thankfully they are eventually successful), but no such slowdowns from the Windows 11 side. As far as I can tell the accounts on both sides are configured the same (I always take the automatic config option when adding an account). I have also looked at the extra account settings required for OAuth2 authentication with Fedora, and believe they are all correct. I have made sends directly from the Gmail server, and they have no delay, so the problem must be related to communication between Thunderbird and the Gmail server on the Fedora side. Interestingly, I do get the following warning message when opening the Fedora Thunderbird: ------------------------------------------------------------ Could Not Authenticate -- Imap(imap.gmail.com) The server for account "imap (imap.gmail.com)" refused the supplied username and password. Do you want to go to the settings for another attempt at logging in, or do nothing? Login failed, sever replied A000002 NO Invalid credentials (Failure) [AUTHENTICATIONFAILED] ------------------------------------------------------------------------------------------- This obviously is a problem, yet it doesn't seem to be fatal, as the server eventually connects, but after the delay. I have checked my account password, and I know it is correct. I would appreciate any insights into what is going on. Tom Rosmond tomrosmond@gmail.com