I’ve just been looking at some of the diagnostic information that’s available for Outlook connections to Exchange (including Exchange Online in Office 365) and one “hidden” feature (actually, it’s not hidden but it’s not very well known) is the ability to Ctrl+right click on the Outlook icon in Windows’ notification area to bring up two extra menu options:

The first of these is handy for bringing up information about the various client-server connections open between Outlook and Exchange (for example the connection protocols being used, port numbers, session types, etc.):

The second allows testing/diagnosis of AutoDiscovery functionality – again, providing a host of information to track down issues:

Combined with the Microsoft Remote Connectivity Analyzer, these are a few tools to help IT admins track down the cause of connection issues.