I cannot send or receive any emails in Outlook because of this error message. The error may be intermittent and Outlook may say Disconnected or Connected.
- Close Outlook, Delete the *.OST file in c:\users\%username%\appdata\local\microsoft\outlook, open Outlook and see if the issue is fixed.
- Close Outlook, open Control Panel, Open Mail, Click profiles, Create a new profile and set it as the default. Open Outlook and see if the issue is fixed.
- Repair Office
- Reinstall Office
Open Chrome (maybe firefox and new edge have the same risk) and see if you have any sketchy extensions. I had a user where an extension was installed that they did not add (related to email) and removing the extension(s) fixed this error message. If this happens to you, run a virus scan. This is the whole reason I am posting this in case it happens to someone else.
Many possible factors may cause issues like this such as network issues or corrupted Outlook profile and datafile. Please check this article and see if could help solve your issue Outlook Troubleshooting: OST Synchronization Error 8004011D-526-80040115-0.