Filter (move) corrupting local mailbox
Thunderbird 91.11.0 (64 bit) on Mac OS 11.6.6 (Big Sur) - IMAP pull
Problem: I have a number of filters that move messages from my (remote) inbox into various local folders. In recent years, about once a month, Thunderbird will hang (spinner turning) while it is (seems to be?) trying to move a message to a local folder. When this happens Thunderbird has to be restarted, and the local destination folder repaired. The problem seems to be related to attachments, especially images of various types.
I need help to define this problem further - specifically to determine which sub-process of Thunderbird is experiencing the problem and the circumstances that trigger it.
Thanks in advance. Chris F