msgFilterRules.dat is blank; Where do my filters exist?
Message filters are, according to various sources, contained in msgFilterRules.dat files.
The only such files I can find on my computer are located in in %APPDATA%\Thunderbird\Profiles\[profile]\Mail\[account]\ and \ImapMail\[account]\ but in each case, the files have zero length and, when opened, have no content.
I should add that Thunderbird is closed while I'm doing this, although it previously was open during the current session.
So, the question is, in which file do the message filters exist, so that I can back them up?
Opaite Mbohovái (1)
Do you have any filters created in Thunderbird? If so, for which accounts? The Mail folder is for POP accounts while ImapMail is for IMAP accounts. There could be more than one profile folders and you're looking in the wrong one. To locate you profile folder, go to Help > Troubleshooting Information > Open Folder (button in the Profile row). If your account is using a non-default location for its storage, then you need to find the correct storage location. That's where the filters file will be.