Exchange2010 and send connector

This is a design question than a problem and would like an expert explain to me.
Our client has Exchange 2010 in two sites.  like Site A and B.
Users at each site uses their own CAS server to send mail out. Everything work fine.
Here is my question , How to avoid the site A mail does not go out via Site B hub transport  and Site B mail does not go out via Site A transport?
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.

Mohammed KhawajaManager - Infrastructure:  Information TechnologyCommented:
I believe Exchange uses servers in its own sites by default.
Rezwan IslamSystems AdministratorCommented:
You can create a separate Send Connector under Hub Transport for each site and add specific CAS servers for for Site A or Site B.
Add specific CAS server to the "Source Server" tab under each Send Connector,
and under the Network tab add the site specific MTA/smart host.

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
sara2000Author Commented:
CAs and HUB server rolls are on one server at each. Yes, source servers are each site's CAS/HUB servers this is default. Does this mean that Site A will not send mail out via Site B so does the Site B?
there is a WAN link between Site A and Site B.
How to avoid that mail is not being routed from Site A to Site B then internet?
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.