Users may have experienced their Outlook desktop client crashing or having problems connecting today. Microsoft has confirmed this problem, identified the cause, and is in the process of rolling out the fix to all users. Due to the scale of the problem it may take several hours for their fix to reach everyone.

Outlook for the web and Outlook mobile clients were not affected by this problem so if you are continuing to experience problems with your Outlook desktop client you can use one of these as a workaround until the fix reaches you.