avast deleted my Thunderbird Mails

  1. moving an infected mail with an attachment to the quarantine container and deleted it from there
  2. close and reopen Thunderbird
  3. inbox is completely empty (Draft, send is still there)
  4. 4000 mails gone
  5. thanx avast

Thunderbird version: Version 2.0.0.19 (20081209
avast version: newest

avast, while processing the mail box, move the entire file to Chest… but why did you delete the file from there?
You would be able to restore and to delete only the infected mail… not the entire mailbox.
Once deleted within Chest, no restore is available. Do you have backup?

For the future, try Mozy online backup (check my signature).