Have you tried restarting with add-ons disabled to see if an add-on might be the cause?

Help menu (alt+H) > restart with add-ons disabled

I disabled add-ons, and waiting for a message to appear that would be mis-routed. (its intermittent). I havent installed any add-ins, so I'm not sure why this would make a difference. I also tried turning on message filter logs, but even though it is checked as enabled, I cant find any log entries anywhere.

If you want filter logs, you need to set that up after setting up the filter. Select the name of the filter, click the Filter Log button, then check the "Enable the Filter Log" box.

logs are working. disabled all add-ins. still not working. here is log entry, and attached is filter. still no explanation for what is happening.

Applied filter "Entertain" to message from notifications@support.mozilla.org - MattAuSupport posted an answer to your question "filters putting messages in wrong folder" at 4/5/2014 8:44:40 PM moved message id = 20140406004440.8199.2382@rabbit-sumo to mailbox://nobody@Local%20Folders/Sales/Entertain

I don't understand either.... could you locate the msgfilterRules.dat file in your profile.

Help menu (Alt+H) > troubleshooting information > Show folder button most likely in the "mail\local folders"

Open in Notepad and paste the content here (IN a message with nothing else... post again afterwards if you like.)

not an exact copy, but close... perhaps we can see something from that.

I cliked on the "Show folder" button as requested, and in the Mail directory, there were two folders, "Local Folders" and "Local Folders-1". the former did not have any msgFilterRules.dat file: only contained "Trash", "Trash.msf", "Unsent Messages" and "Unsent Messages.msf" files. The "Local Folders-1" dir did contain a msgFilterRules.dat file, but that file only contained two lines of text:

version="9" logging="yes"

Ok I took a guess and it was wrong.... the same file appears in each account folder, not just local folders. Imap accounts in IMAPMAIL instead of mail also have the file.

just poke around and find the one entertain will be in.

I just sent you a private message with the Entertain msgFilterRules.dat file. had too much private info to post publicly. let me know if you didnt get it. One notable thing was that the Entertain condition statement had an empty condition at the end, ie:

condition="OR (from,is,info@somebody.org) OR ... OR (from,is,)"

I edited the rule in the filters gui, and got rid of an empty rule box at the end of the list. I'll see when you reply if that resolves the situation. Dont know why only certain messages would get filtered into Entertain. most of them are working properly.

If you have many filters and are wondering which filters move mail to a certain folder, you can test the new feature I added to my quickFilters addon:

Tool to find all filters that move mail to a specific folder

You simply right-click the folder in the folder tree and select "Find Filters..."