I have a multi-tennant, Exchange 2007 environment that I am trying to migrate to Exchange 2013. I think I'm ready to swing the DNS over, for co-existence, but want to test first. I have updated my Hosts file, and am seeing odd behavior in my tests. I wonder if my test is flawed, or if there is a misconfiguration somewhere in my Exchange 2013 environment.

The following IPs modified, but are correctly related to each other and I'm sure they are all able to communicate with each other. Here is what I have :

+ 2007 
- CAS/HT = 10.x.x.2/200.x.x.2

+ 2013
- Load balancer = 10.x.x.3/200.x.x.3
- CAS-MBX1 = 10.x.x.4
- CAS-MBX2 = 10.x.x.5
- CAS-MBX3 = 10.x.x.6

+ Hosts file
200.x.x.3 webmail.hosteddomain.com autodiscover.hostedserver.com autodiscover.customer1.com autodiscover.customer2.com
200.x.x.2 legacy.hosteddomain.com

The test mailbox for Customer 1 is on Exchange 2007 and the test mailbox for Customer 2 is on Exchange 2013. 

Here are my tests, and their results:

+ Test 1
1. webmail.hosteddomain.com -> enter Customer 1 credentials -> browser shows "Redirect loop detected" or "The website declined to show this webpage (http 403)"

+ Test 2 
1. Log into Windows with Customer 1 credentials -> open Outlook -> name detected -> "Your account was redirected to https://autodiscover.hosteddomain.com/autodiscover/autodiscover.xml" -> Allow -> mailbox displayed

+ Test 3
1. webmail.hostedserver.com -> enter Customer 2 credentials -> mailbox displayed

+ Test 4
1. Log into Windows with Customer 2 credentials -> open Outlook -> name detected -> "You must restart Outlook for these changes to take effect" -> OK -> without restarting Outlook, "Outlook cannot log on. Verify you care connected to the network and are using the proper server and mailbox name." -> OK -> Microsoft Exchange server: CAS-MBX3, Mailbox: Test User -> check name -> "Outlook cannot log on. Verify you care connected to the network and are using the proper server and mailbox name." -> OK -> "The name cannot be resolved. The action cannot be completed."
2. Change Microsoft Exchange server to serverGuid@customer2.com -> check name -> "Outlook cannot log on. Verify you care connected to the network and are using the proper server and mailbox name." -> OK -> "The name cannot be resolved. The action cannot be completed."
3. Open Hosts file and change webmail.hosteddomain.com to 10.x.x.3 -> check name -> "Outlook cannot log on. Verify you care connected to the network and are using the proper server and mailbox name." -> OK -> "The name cannot be resolved. The action cannot be completed."

So my Exchange 2007 user cannot log into OWA and my Exchange 2013 user cannot use Outlook. What am I missing here?

Thanks.

• Edited by mhashemi Tuesday, May 26, 2015 4:31 PM fixed a typo

Right, but I can't change the production environment, until I have tested. How do I test without impacting prod?

• Edited by mhashemi Wednesday, May 27, 2015 2:23 AM

I realized that, since we have a wildcard certificate, I can use testmail.hostedomain.com (pointed at 200.x.x.3) as a test for OWA+2007. Since testmail and webmail.hosteddomain.com are different, it is the equivalent of using webmail and legacy.hosteddomain.com.

Now I just need to figure out how to test Autodiscover for my Exchange 2013 mailbox (customer 2).

Hi ,

For autodiscover, we just configure it to point to Exchange 2013, when mailbox which is on Exchange 2007 connect to Exchange 2013, Exchange 2013 CAS will proxy to Exchange 2007 CAS server. We could use the following command to check if we have changed Exchange 2013CAS autodiscover into https://autodiscover.hosteddomain.com/autodiscover/autodiscover.xml:

Get-AutodiscoverVirtualDirectory -Server <Exchange 2013CAS Name> -Identity "<Exchange 2013 CAS name>\autodiscover(autodiscover.hostdomain.com)"

In addition, contact you ISP to update MX and Autodiscover record to point to Exchange 2013.

If there are any questions regarding this issue, please be free to let me know.

Best Regard,

Jim