New Office365 Setup and Old Mail Server/Domains


  • We've recently moved our company onto the Office365 platform and this is our first foray into using Exchange.  For the most part everything is set up and functioning properly with our main company domain.

    However, for a variety of reasons, we have kept our old mail server running as we need it for sending automated emails from our many legacy domain names.  (Moving these domains to Office365 was not an option due to sending limits and services like MailGun and MailChimp haven't worked out for us)

    An issue is we have many clients and old newsletter subscriptions that still send mail to our old legacy domains which end up on our old server.  For now, we have all these old accounts simply forwarding to their appropriate Office365 account.  This is working but we have to check multiple spam filters and other aggravations have arisen.  We're wondering if there's a better way to set this up?

    So, what we need is the old server to stay running with legacy domains for our automated processes to use to send.  But, we want incoming mail for legacy domains to route to Office365.

    Thanks for any suggestions.

    • Edited by pmascari Wednesday, November 2, 2016 4:46 PM
    Wednesday, November 2, 2016 4:45 PM

All replies

  • Redirecting the MX records for said domains to O365 is not an option? If you are only using the servers to send mail, where the MX points shouldn't matter.
    Wednesday, November 2, 2016 6:54 PM
  • Thank you for the reply.  I'm not an email expert by any means so I need to ask....would redirecting the MX records in any way affect whether the messages we send get classified as spam?
    Thursday, November 3, 2016 2:56 PM
  • Hi pmascari,

    Change MX records only affect the direction of receiving emails, it won't affect sending messages.

    Make sure your SPF record has configured correctly.

    Best regards.

    Jason Chao
    TechNet Community Support

    Please remember to mark the replies as an answer if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact
    Friday, November 4, 2016 1:55 AM