I have 21 filters set up in Thunderbird (originally on the Mac, now on Windows). This is for an IMAP account. Most of the filters are simple, one match, mark message as read, move to a folder. A few have multiple matches, but the same mark read and move to folder steps. Some filters work fine, some do not work at all. The ones that are not working are the simple single match ones. There's nothing in the filter log showing what the issue might be. The filter in question doesn't show up. What can I do to track down what the issue might be? Thanks.