Exchange 2003 to 2010 migration external MX records

Posted on 2011-05-03
Last Modified: 2012-06-27
When adding a 2010 exchange server to a 2003 exchange environment when is the best time to change the MX records/public DNS to point to the new 2010 exchange server to have the least amount of down time?   Should this be done before migrating mailboxes or after all have been moved?
Question by:mattconroy
    LVL 8

    Accepted Solution

    once exchange 2010 HT is in place, proper receive connectors are created. then you can create send connectors as well so that 2010 HT will be responsible for all emails in & out.

    if you are unsure at any point, change first mx to ex2010, add a lower priority mx to ex2003 so that you wouldn't loose any emails.  
    LVL 24

    Expert Comment

    Before moving mailboxes.

    Get the mail flow changed. This is done on your firewall, not external public DNS, unless you are changing the IP. Get your firewall to route all port 25 traffic to 2010 HUB server.

    Check for full steps.
    LVL 6

    Author Comment


       So is it completely acceptable to have multple mx records for the same pointing to different Exchange 2010 Servers? Keeping in mind that they will have different priorities. Is this tru event if the exchange servers are in defferent AD Forests as well?


    Featured Post

    Promote certifications in your email signature

    Has your company recently won an award or achieved a certification? They'll no doubt want to show it off. Email signature images used to promote certifications & awards can instantly establish credibility with a recipient and provide you with numerous benefits.

    Join & Write a Comment

    Suggested Solutions

    Granting full access permission allows users to access mailboxes present in their database. By giving full access permission one can open and read the content of any mailbox but cannot send emails from that mailbox.
    Check out this infographic on what you need to make a good email signature that will work perfectly for your organization.
    In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
    This video discusses moving either the default database or any database to a new volume.

    754 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    24 Experts available now in Live!

    Get 1:1 Help Now