I have turned OFF all message filter instructions, yet even after restarts, Thunderbird is moving messages to 'Trash'. This has been happening for a week or so.

Ref: Thunderbird 60.3.1 32 bit on my 64 bit Windows 7 Pro, all up to date.

What I do:

Viewing Inbox, I down-arrow to the next message, which 20% of the time is auto-trashed and the subsequent message is revealed.

I do Edit / Undo ( Ctrl-Z should also work) and then Thunderbird retrieves the trashed message.

This is bizarre and a thing I can't explain.

  • Junk mail filtering? – Hannu Nov 27 '18 at 16:41

When you say you turned off all message filtering, you may not have turned off what's moving your messages.

There are different filters that are controlled in different places:

  • Filters; these are controlled through tools | message filters, and may include both filters provided by Mozilla, like SpamAssassin, and rules you create yourself.
  • Junk Mail Filtering; with general options accessed through Edit | Preferences | Security | Junk.
  • Junk Mail filtering is turned on and off at the account level, accessed through Edit | Account Settings then within each account Junk Settings.

The junk mail filtering is a learning system, but it comes with some rudimentary rules built in as a start, and is turned on by default.

If you verify that all filtering is actually disabled, there are many other things that can cause this kind of symptom. There is a whole Mozilla Knowledge Base article on disappearing mail. Not all of the possibilities listed match your symptoms, but some of the possibilities include:

  • corrupted index files (in your case, that would be a good bet, but there are other possibilities)
  • anti-virus software deleting messages
  • incoming messages sent with incorrect date
  • messages read with a different email client

The solutions depend on the cause, and they're covered in that knowledge base article.

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Not the answer you're looking for? Browse other questions tagged or ask your own question.