Microsoft Outlook  official

Users experiencing issues with deleted and/or duplicated emails will be pleased to know that Microsoft has identified the problem.

A Microsoft Support Knowledge Base article details the cause of, and workaround to, the issue between Microsoft Outlook 2016 and POP3 client/server protocol.

The culprit is an advanced Outlook 2016 setting, “Leave a copy of messages on the server,” and the specific issue is related to the “Remove from server after <x> days” option.


 

The article describes the following problems related to this issue:

  • After Outlook downloads your email, all the email messages on the server are deleted from the Inbox.
  • Email messages are downloaded multiple times in Outlook, causing duplicate items.

 

These checked settings can cause the duplicate or deleted mail issue.
These checked settings can cause the duplicate or deleted mail issue.

 

Microsoft outlines two possible workarounds to the problem:

  • Use IMAP instead of POP3: If your email server supports IMAP connections, you can create a new profile configured to connect using IMAP. This will not import your previous email data; however, you can import it from the .PST file or switch back to your POP3 profile to access it. This is a valid option only for those users whose ISP supports IMAP connections, however.
  • Revert to an earlier version of Outlook 2016. Instructions on how to do so are given in the Knowledge Base article.

The article also offers a solution to getting rid of the duplicate emails, but stresses that users should back up their Outlook 2016 data before deleting the cloned emails.

Microsoft is currently working on a long-term solution to the problem and will update the Knowledge Base once more information becomes available. In the meantime, the workarounds offer a temporary solution.

SOURCE: Microsoft.