Avatar of confusionmaker
confusionmaker
Flag for United States of America asked on

Exchange 2003/Exchange 2010 coexistence mail flow

We are in the process of migrating our email from Exchange 2003 to Exchange 2010.  We currently have 3 Exchange 2003 servers.

Exchange 2003 setup:
Server 1 - Primary mailbox server.  Internet mail passes through this server to a smarthost.
Server 2 - OWA server.  We also host an email marketing application that sends marketing emails thru this server, bypassing the smart host.
Server 3 - Gateway for a Groupwise email system. (Not concerned with this at the moment.)

We recently installed the CAS and Hub Transport roles into our environment on a single server.  Everything is working, internal mail is flowing, external mail is flowing.  However, all mail is now passing through the 2010 Hub Transport server.  We were under the impression that during coexistence, Ex2003 mail flow would not be changed.  

This has not stopped mail flow, however the HT role has been configured to go through the smarthost.  The problem we are running into is when an email marketing campaign is submitted, our regular internet mail is delayed in the queue waiting for the campaign to finish.  We would like to see the email marketing campaigns continue to pass through the Ex2003 server for the time being.  The email marketing software is configured to use the Ex2003 as its smtp server, but mail still passes through Ex2010 HT.  Is there a way we can force mail through Ex2003 for the time being?
ExchangeEmail Servers

Avatar of undefined
Last Comment
confusionmaker

8/22/2022 - Mon
ASKER CERTIFIED SOLUTION
isaman07

Log in or sign up to see answer
Become an EE member today7-DAY FREE TRIAL
Members can start a 7-Day Free trial then enjoy unlimited access to the platform
Sign up - Free for 7 days
or
Learn why we charge membership fees
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.
Not exactly the question you had in mind?
Sign up for an EE membership and get your own personalized solution. With an EE membership, you can ask unlimited troubleshooting, research, or opinion questions.
ask a question
confusionmaker

ASKER
Thanks Isaman.  Is there not a way to set it up so that the email marketing is sent out one of the Ex2003 servers and all other mail is sent out the Ex2010 server?  I misunderstood what I had read before the install of the Hub Transport.  Thought that Ex2003 would continue to travel the same path to the internet.  Did not realize Ex2010 would take over smtp.
isaman07

Unfortunately not.i strongly recommend the use of standalone smtp server for mass mailing
confusionmaker

ASKER
Isaman, thanks again for your input.  Unfortunately a stand alone smtp server is not an option for us.  

We did however, figure this one out.  We thought we could resolve the backed up queues by sending the marketing email through the Ex2003 server.  We found out that mail was being delayed because we were using a smarthost, which is not recommended for Exchange 2010 by our spam vendor.  We discovered that utilizing private outbound DNS was the solution instead of the smarthost.  This resolved our queuing problems.  All mail is flowing smoothly through Ex2010.
Experts Exchange has (a) saved my job multiple times, (b) saved me hours, days, and even weeks of work, and often (c) makes me look like a superhero! This place is MAGIC!
Walt Forbes