I've been using Thunderbird for years. I shutdown my computer (MacOS Sequoia) and went away for a few days, and now Thunderbird hangs when I try to use it. I have one main email account which I access with POP, and a couple of other accounts which I access with IMAP. I can access the downloaded messages in the Inbox of the POP account that I downloaded before going away, but I can't read any other folders (I have many folders since I've used Thunderbird for so long), or access the IMAP accounts. Thunderbird shows that I have new mail waiting on the POP server, but it hangs when I try to download them. It does not show mail waiting on the IMAP accounts, although I know new mail is there. I have tried re-installing Thunderbird, and rebooted the computer, with no change. When Thunderbird hangs, it eats memory until the system runs out, and I have to use Force Quit to terminate it. It's the first time I've had a problem with it!