emails vanish
Emails in my inbox magically get deleted after only a few days. All settings indicate that emails should never be deleted. This problem only exists on one account, the other 2 accounts retain emails without issue. Please help
ప్రత్యుత్తరాలన్నీ (1)
if your account is IMAP the server will be canonical with regard to retention policies. Despite telling Thunderbird to delete nothing, it will delete whatever the server deletes, that is how synchronization works.
If you also get your mail on your phone and delete the message there, it will be reflected in Thunderbird as well.