Outlook 2016 stopped updating cause
The latest update for Outlook 2016, build 16.0.6568.2025, is causing problems for people who use POP3 accounts and have Outlook set to leave mail on the server for a period of time.
Instead of deleting the aged mail from the server, it deletes all of the mail. Until this problem is fixed, there is a simple workaround: users can uncheck the option to delete mail after a period of days, while leaving the "leave on server' setting checked.
The leave on server setting is on the Advanced tab.
Untick the option to delete it after a specific number of days. there is second issue with this update and POP3 accounts.
The usual fix when this happens is to not leave mail in the Inbox on the server, however, this won’t help someone who wants to leave mail on the server.Running Win Sweeper once per day (using automatic scanning) will ensure that your computer is always clean, running fast, and free of 2016 errors related to temporary files.