Outlook – Need to restore emails that Outlook deleted from the mail server

1. Go to Options -> Advanced -> Config Editor.

2. Find the Name mail . pop3 . deleteFromServerOnMove

3. Set it to True.

True: Delete the copy of the message on the POP3 server if you move or delete the message.

False(default): Only delete the copy of the message on the POP3 server if you delete the message.

That's it, restart Thunderbird. You need to press 'Get Mail' everytime you want to sync with the email server, in order for you to make sure messages in the application is in sync with the email server.

The following should be emphasized to realize the sync with the server. You will not see your server message disappear upon the initial Get Mail download (new messages downloaded). After you process your Inbox in Thunderbird by deleting/moving a new message, then do another Get Mail which will delete the new messages previously downloaded on the server (put in sync).

Note: If you have older messages in your Thunderbird Inbox, they will not be deleted from Server. Delete them manually from server. From then on, any new messages you download, then process (delete/move), and then do the sync by doing Get Mail again WILL be deleted.

In respond to Dave Rook, he has given me an idea how to set up IMAP in MS Outlook. I have the same issue like you did. I set up Pop3 yahoo for my MS Outlook. I never unchecked the box saying "Delete mails from the server after downloading to my MS Outlook. I did not like the idea of forwarding all my emails from MS Outlook to Yahoo again.

Here is the solution.

Do not delete Pop3 yahoo account from MS Outlook. If you did that, you will eventually delete all your emails in MS Outlook.

Now, create IMAP account.
IMAP configuration has to match below

Incoming Mail (IMAP) Server - Requires SSL

Server: imap.mail.yahoo.com Port: 993 Requires SSL: Yes Outgoing Mail (SMTP) Server - Requires TLS

Server: smtp.mail.yahoo.com Port: 465 or 587 Requires SSL: Yes Requires authentication: Yes

Once you have done that, go ahead and synchronize with the yahoo server. Make sure you input your username and password correctly. After MS Outlook has downloaded all the yahoo mails into MS Outlook IMAP configuration, perform copy and paste of all the missing emails into your IMAP configuration folder from Pop3 configuration mail folder in your MS Outlook. Once you have pasted all the email, click send and receive to synchronize with yahoo server. Once done, open your web browser, log into yahoo mail. You will see all your missing mails are back into the server.

Good luck