I receive hundreds of messages on my account ([edited email from public] @att.net) daily, mostly bulletins, and I (attempt to) download daily (used to download more than one time of day) into my migrated and upgraded (to 102) POP3 Inbox. I had allowed the Inbox to grow to over 400K messages, and have planned to prune it from the oldest to a more reasonable size. However, the interval between the latest POP message and the latest IMAP message (retrieved on my iPhone with Apple's default mail app) has lengthened to 4 days! There is no way to check how much, if any, actual progress has been made. I got rid of the "get messages" on starting TB, and killed the formerly 5 minute interval first to 60 minutes, then to no automatic "get messages" at all (IOW, it only tries to start a download when I click the button). If I try to restart the download, I get an error message "The account [edited email from public] @att.net is being processed. Please wait until processing is complete to get messages." But the "processing" never seems to complete. There is no progress bar (actually, the progress bar goes to 100 percent immediately upon starting a download, making it useless), there is no inquiry to find out which message is currently being "processed," and there is no message saying that the download cannot make progress (when it DID complete, it said either "no new messages found" or "downloading xxx of xxxx messages," with xxx being incremented until it reached xxxx). I have not seen any such message in over 3 days; the iPhone's IMAP logic constantly updates with no problem, so I know the messages are going onto the server (at least the IMAP server), but the latest message downloaded on the POP side is 96 HOURS old! Right now, the iPhone has messages up to 1917 on 10/24/2022, but the computer's latest retrieved message is timestamped at 1917 on 10/20/2022 with about 700 other messages waiting to be downloaded. It is quite cumbersome to work with such large numbers on the iPhone alone, with about 1 percent actually requiring action. Is there ANY utility that can tell me why the checking for new messages ALWAYS starts with the oldest messages going back to 2016, and how far it has gone when it seems to be "stuck?" How can I set up the download to start more recently, as in no more than a year? How can I stop and restart the process, other than restarting TB itself? Please, someone with technical knowledge about this, answer these questions! Windows 10 running under Bootcamp on iMac; migrated from Windows 10 on Toshiba Satellite Radius 15; Tbird 102 is when problem started. Email [edited email from public] @att.net, phone [removed phone# from public] , have Mozilla account, TB, FF, and VPN.