You have Microsoft Outlook 2016 (build 16.0.6568.2025) configured to download your email by using POP3 with leave a copy enabled, and you experience one of the following symptoms.
1. After Outlook downloads your email, all the email messages on the server are deleted from the Inbox on the server.
2. Email messages are downloaded multiple times in Outlook, causing duplicate items.
This issue may occur if you have Outlook 2016 version 16.0.6568.2025 configured to use POP3, and if you have the Leave a copy of messages on the Server option enabled.
Microsoft has acknowledged that this is an issue with Outlook and a workaround and suggestions have been published at https://support.microsoft.com/en-gb/kb/3145116. However, these are not ideal in all cases. We would recommend rolling back to the previous build till Microsoft fixes the issue.
To roll back to the previous build of Office, you can follow the steps below.
1. In Outlook, select File, Office Account, Update Options, Disable updates
2. Set a reminder on your calendar to re-enable updates ~April 1
3. Open an elevated command prompt as administrator then run the commands below
cd C:\Program Files\Common Files\microsoft shared\ClickToRun>
officec2rclient.exe /update user updatetoversion=16.0.6366.2068
Version history for Office 365 customers is published at