Comment 4 for bug 1853007

> leaving thunderbird running for extended periods is a perfectly
> normal thing to do

Arguably, so is leaving files in /tmp while the application is running.

Leaving files around (containing potentially sensitive information such as e-mail contents) after the application has exited, though, is not something I would expect.

May I suggest you file an upstream bug at https://bugzilla.mozilla.org/enter_bug.cgi#h=dupes%7CThunderbird and share the link to it here? Thanks!