Outlook 2016 will not connect to Exchange 2016 following SSL install

Hector Jones
Hector Jones used Ask the Experts™
on
We have a new build Exchange 2016 server (on Server 2012 R2) and several Outlook 2016 clients. When we attempted to connect the clients with the default settings on Exchange (no SSL added, namespaces not changed etc.), apart from a certificate error which we could ok to continue, the clients connected properly.

Today, we added a GoDaddy SSL and changed all our namespaces to the external address e.g. office.domain.com. Now, the clients still give the certificate error but they also won't connect to Exchange with the error :

The action cannot be completed the connection to Microsoft exchange is unavailable outlook must be online or connected to complete this action.

We have an identical setup in two other offices (none are linked) and they work perfectly with the same settings. We have double checked their namespaces, DNS, IIS bindings and run Outlook test settings, but nothing will make these clients connect. The only difference is the faulty office is using Cumulative Update 2.

I'm slowly going insane here so would greatly appreciate any help to resolve this. I have tried rolling one client back to Office 2013 but get the same error.
Comment
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Jeffrey Kane - TechSoEasyPrincipal Consultant
Most Valuable Expert 2016
Top Expert 2014

Commented:
Outlook 2016 uses only Autodiscover to connect to an Exchange Server.  If you've created a Forward Lookup Zone for your external domain in your Windows DNS, you need to be sure you also have the proper autodiscover record included (generally just a cname record which points autodiscover to server.domain.com).

To troubleshoot, from a workstation you can hold CTRL down and right click the Outlook icon in the status area of the taskbar to select "Test e-mail autoconfiguration" and it will step through what Outlook is seeing as it tries to connect.
Jeffrey Kane - TechSoEasyPrincipal Consultant
Most Valuable Expert 2016
Top Expert 2014

Commented:
Oh, and if you've done all that then just create a new Outlook profile for the affected systems.

Author

Commented:
Thanks Jeffrey, I've run the Outlook Test email configuration and it all looks correct and (apart from unique office name of course), completely matches the other two offices configuration.

I've also tried creating new profiles but get exactly the same error on all the machines.

I've just re-checked all namespaces, both via the gui and PowerShell and everything is exactly as it should and have triple checked DNS can resolve both internally and externally.

I actually wish I could find an error somewhere to fix, but these clients just will not connect.
Should you be charging more for IT Services?

Do you wonder if your IT business is truly profitable or if you should raise your prices? Learn how to calculate your overhead burden using our free interactive tool and use it to determine the right price for your IT services. Start calculating Now!

Jeffrey Kane - TechSoEasyPrincipal Consultant
Most Valuable Expert 2016
Top Expert 2014

Commented:
Then your next step is to download and run the Microsoft Connectivity Analyzer Tool found here:  https://testconnectivity.microsoft.com (on the "Client" tab)
Todd NelsonSystems Engineer
Top Expert 2016

Commented:
Try restarting the Autodiscover App Pool on the Exchange server where the mailbox resides; or restart the server if you haven't already.

https://oddytee.wordpress.com/2016/08/16/outlook-client-does-not-connect-to-mailbox-on-exchange-2016/

Author

Commented:
Thanks again for the help.

The server has been restarted and I've restarted the Autodiscover pool, no change. These are all new mailboxes on a new server although we did pst mailboxes over via Outlook from our old SBS2008 server.

I ran the Analyzer from the Client tab and it fails on AutoDiscovery connectivity. Everything else it passes. Looking at the failure though, it is looking just at domain.com but our namespace uses office.domain.com. Is the Analyzer confused or have I missed something ?

I've also just run the Analyzer on a client pc in another office that works perfectly and get the same failure, again it seems to look at domain.com not office.domain.com.
An update to this, I raised a support call with Microsoft and the problem was that IIS authentication was completely blank, something he had never seen before. He restored that and everything works perfectly now.

Author

Commented:
Resolved by Microsoft support.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start Today