Adding additional Exchange 2010 server in new site - how to handle ActiveSync, OWA, etc

2x Exchange 2010 servers in different AD sites
1 on subnet A (colo), 1 on subnet B (office)

Exchange A is the original one and I have added Exchange B to the mix. Everything seems to be okay. I have moved a few old mailboxes, set up the SSL certificate, DNS, etc.

Without adding another server, how do I keep this migration seamless if I do it in stages? It's going to take a long time to move mailboxes from one Exchange to the other, but I want ActiveSync, Outlook Anywhere, OWA, etc to keep working and not have to upset a bunch of users.

I see this but wondering it is just as easy as
Set-OWAVirtualDirectory -Identity "Contoso\owa (Default Web site)" -CrossSiteRedirectType Silent ?

Do I need to do anything else for Outlook Anywhere or ActiveSync?

Once someone has been redirected to the new server, do they need to update the config on their mobile device(s)?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Simon Butler (Sembee)ConsultantCommented:
Outlook Anywhere and ActiveSync will proxy to the other server, although if you publish a new URL for Outlook Anywhere in the second location, Autodiscover should pick that up and correct the clients.

OWA will redirect, as long as you have forms based authentication enabled and the same format for authentication set on both sites.

If a NEW connection is made in ActiveSync, and they use Autodiscover, then it should be pointed to the correct server, rather than going through the proxy.

You can test this for yourself with a test account and the Microsoft test site at 
Don't do an Autodiscover test, but choose to put in the manual information. Enter the "wrong" site URL and you should find it still connects.


Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
mvalpredaAuthor Commented:
I have all the URLs published and an SSL cert installed. I will try a test user and see what happens.

If all is correct, Exchange will update the client and the user should not even notice?
Simon Butler (Sembee)ConsultantCommented:
As long as they are in different AD sites, then Exchange will update the Outlook clients automatically. ActiveSync is a different matter.

Simplify Active Directory Administration

Administration of Active Directory does not have to be hard.  Too often what should be a simple task is made more difficult than it needs to be.The solution?  Hyena from SystemTools Software.  With ease-of-use as well as powerful importing and bulk updating capabilities.

mvalpredaAuthor Commented:
I wasn't as worried about Outlook as I was about ActiveSync. I hate reconfiguring phones/tablets/etc
Simon Butler (Sembee)ConsultantCommented:
ActiveSync is very hit and miss because it is down to the individual implementation of ActiveSync by the vendor - completely out of Microsoft's hands. Some of them will regularly query Autodiscover and will therefore get the new configuration. Some do it just once. Others cannot do it properly at all.

If you have your end users on the same device, then I would test it. Otherwise you are going to have to expect some failures.

mvalpredaAuthor Commented:
Do I need another _autodiscover._tcp. record for external DNS?
Simon Butler (Sembee)ConsultantCommented:
Autodiscover can be handled by any server in the org. You do not need to have Autodiscover going to the second location as well.

mvalpredaAuthor Commented:
Then even if the mailbox is on a different server the autodiscover will get that figured out for them?
Simon Butler (Sembee)ConsultantCommented:
Autodiscover is a domain wide thing - it doesn't matter what server the client hits, it will get the correct information.

Remember Exchange is a domain product - the servers are just containers for the data. The configuration is stored in the domain.
Furthermore the CAS role does not "belong" to any specific mailbox server. CAS can be used by any mailbox in any location.

mvalpredaAuthor Commented:
Still doing some testing. Have not moved any mobile devices yet....
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.