I'm writing this article to hopefully save someone the pain that I've had in connecting a Mac to our Exchange 2010 server, because it has been painful. I've spent the past couple of weeks trying to get it to connect with some wild goose chases and in the end found a very simple solution.
The problem I was getting was whenever I tried to connect Outlook for Mac to Exchange it kept coming back with unexpected data received. The first step in troubleshooting should be to turn on the error logging.
From the Window menu select Error Log then click the Settings cog and select Turn on Logging for troubleshooting.
The log file produced will provide some insight into what Outlook is trying to do. Although this is where the wild goose started. I could see that when trying to perform autodiscovery it was hitting our main website e.g. domain.com/autodiscover - this was passing back a custom page not found which I thought was causing problems for a while, so I added hosts files to point to loopback addresses which seemed to get past that bit. Then I could see it trying autodiscover.domain.com and everything looked ok but I still couldn't send any emails.
We'd been having trouble with updates on our CAS server for sometime so I put it down to an issue with the server. Because we had spare licenses I setup another CAS server. But still had issues connecting.
I looked at EWS policies, made sure EWS wasn't disabled. Even checked that EWS wasn't disabled on the mailbox.
To cut a very long story short for some reason I thought about authentication. Then I thought I'd check the authentication on EWS website. From there I checked the IIS logs and could see 401 errors - unauthorised but no 200 successes. Then with the help of good old google found articles about turning basic authentication on on the EWS website.
set-WebServicesVirtualDirectory -Identity "EWS (Default Web Site)" -BasicAuthentication $true
Did this on both our CAS servers and hey presto all good.
I hope this helps someone out there.