Hello there Alex '''''Asking for linux''''' Is it true ?do you use Linux>?okay. This map often appear as linux user. Answer ; this map is there because snap does not like s to have all this /tmp stuff. So it creates an folder thunderbird.tmp and has a storage function to for data that came from email downloads. And exactly appears at launch .. '''''Looking at linux ''''' Recommendations are to switch . Go and install .deb and before that erase snap. Download from trusted places. In my text it shows up to download at mozilla ppa ;the version from the Mozilla PPA (using apt/deb). Or ignore and hide this map , these data clones and map are not more than temporary files in a map. '''''Use''''' It might disappear if you empty that map . Not really direct ,but it could happen at certain moments. Or you might be lucky if thunderbird plans to have that cleanup moment.