Missing folders/emails in Unified Folders view

Close Thunderbird, go to the profile folder and delete virtualFolders.dat file and Mail folder. Start Thunderbird.

Exporting/Importing Message Filters

When you create a message filter, each filter is saved within the emails folder, in a file called msgFilterRules.dat, so when importing or exporting you’ll need to retrieve the file for every email address.

C:\Users\<USER>\AppData\Roaming\Thunderbird\Profiles\<PROFILE>\ImapMail\<EMAIL>\msgFilterRules.dat