I'm having difficulty getting message filters to do the job I want. My primary email account is an Outlook 365 account, accessed from Thunderbird via IMAP. This problem started with version 91.2.0, when I moved to a "native" connection to my Outlook account. In the past I used the ExQuilla extension, and the filtering worked as desired. It seems that message filters are being applied to ALL of my mail folders, rather than just my primary inbox. The problem is that filter "A" moves a message from my primary inbox to an alternate folder, then filter "B" comes along and moves it again. It doesn't seem to matter what order I declare the filters, since the filter list is executed more than once. For a simple example, I have the following: Filter A: "Whitelist": Matches any "From" address from a trusted sender/domain; move message to "Whitelist" folder. Filter B: "Other": "Does not match" if "From" my domain; move message to "Other" folder. The intent is to apply A, then B, but only to fresh, incoming email. However, filter "B" gets applied to the "Whitelist" folder, effectively undoing its action. I could solve this by making "Whitelist" and "Other" local folders rather than Outlook (IMAP) folders, but that would limit my access to those emails. What I really need is to run the filters ONLY on a selected folder (i.e., my primary Inbox).