Recovering deleted emails on IMAP server with Thunderbird

Question

I have an IMAP mail server and use Thunderbird as my client. I didn't understand the sychronization of client-server using IMAP vs POP. My IMAP server was filling up, so I logged onto the server and deleted the Inbox thinking that Thunderbird had local copies of the mail.

When I opened Thunderbird, it synched against the IMAP server and marked all my email as deleted. The emails still exist in the {path}/thunderbird/profile/default/INBOX file fortunately. After some research on the net, I edited that file and changed all the “X-Mozilla-Status:0001" to "“X-Mozilla-Status:0000".

When I brought Thunderbird back up, the emails were still gone. Does anyone know how to recover these?

Answer 1

IMAP and POP are not the same! POP is a transfer protocol, pulling e-mail from the server to the client. IMAP is a synchronization protocol, keeping e-mail on the server, and usually keeping a local cache version.

IMAP has a two stage delete, though most clients don't separate them. They are: Mark as Deleted, and Purge Deleted. Like I mentioned, most clients do both at the same time.

Once an e-mail is purged from the server it should be flushed from any local caches, permanently deleting the e-mails, upon next synchronization. Changing a cache will not change the server.

Accidents are the reason you take good backups; so you can just restore the e-mails.

Answer 2

so I logged onto the server and deleted

do you mean that you ssh'ed into the server? what kind of server is it? if it's running a snapshotting filesystem, it may be possible to recover the inbox from the snapshots...

Answer 3

I had a similar problem - through some quirk a bunch of emails disappeared from my IMAP server, but remained in the INBOX and Sent files on the local drive. I was unable to coerce Thunderbird to restore those emails onto the IMAP server directly, so I went with another approach:

• Create a POP3 account with the same credentials as the IMAP one, but make sure this account is unable to connect - don't enter your password.
• Shut down Thunderbird, and navigate to /Profile/randomname.default/Mail/hostname_of_your_server/
• Double-check that this is indeed your freshly created dummy account and not some other valuable, but similarly named POP3 account.
• Copy over the Inbox file containing the deleted emails, overwriting the one from the dummy account, and delete the inbox.msf file that was also in that dummy account folder.
• Start Thunderbird - notice you have all your emails back! Both the deleted and the undeleted ones are visible in the dummy POP3 account.
• Now grap the Thunderbird "Remove duplicates (Alternate)" extension from here: Remove duplicates (Alternate).
• Using the above extension, set the IMAP Inbox as the "Set original message folder(s) for next duplicate search", and run the "Remove duplicates" on the dummy POP3 Inbox.
• Move the duplicate messages to Trash.
• Move the remaining messages from the POP3 Inbox, to the IMAP Inbox. Thunderbird will re-upload all the messages automatically to the IMAP server.

Done!