EXTEST_33788774A21E4 user is not there (Exchange Test User)

If the EXTEST_33788774A21E4 user is not there and needs to be to run the test-outlookconnectivity you need to do the following:

Then open Exchange Management Shell and navigate to the Scripts directory under where you installed Exchange, and run the new-TestCasConnectivityUser.ps1 script to recreate the mailbox-enabled user. It shouldn't matter that it creates a new mailbox; there shouldn't be any data in it that is of any importance.

Again, I don't think this will fix Outlook Anywhere, but it will allow you to test it.