Monday, August 26, 2013

Exchange 2007 (SP3) - migration (staged) - Exchange Online (Office 365) - Part 8 - DNS

DNS settings for Exchange Online

At this point in the migration, mail is still directed to the onsite Exchange server because the MX records still direct mail to a domain name associated itself with the IP address of the mail server (or the external interface of the organization firewall, for example).

Therefore, as one of the final steps of the migration process, we need to adjust or create the following records, as presented in the domains section of the Office 365 portal.
First, go the the domains section and select the domain for which you want to manage the DNS records.

Click on "View DNS settings". The screen below displays:
These are the DNS records that must be created or adjusted in the web interface of your DNS provider. Directions for some major providers are available. Otherwise, please consult the documentation of your provider.
In my case, I had to do the following:
  • Change the A record for autodiscover - pointing to the external IP address of my firewall - to a CNAME record - pointing to Note: yes, if you select what was an A record, you can click on a radio button for A or CNAME.
  •  Adjust the MX record so it no longer points to but rather the target shown in the illustration above.
  • Create a SPF record (values indicated above).
The results were excellent. Within 30 minutes I could send and receive messages (tested with both Outlook and OWA).
I turned off the onsite Exchange 2007 server so there was no possibility that things were only working because it was still available (since it was not).
This series of posts on (staged) migration to Office 365 has been long but yet incomplete. There are many other subjects that could be examined, notably migrating public folders and accessing email via ActiveSync.
However, I want to avoid limiting myself to a single subject. After having composed many posts about Exchange and migration to Exchange Online in particular, I'm going to change subjects (finally) and take a look at Microsoft's latest server OS, Windows Server 2012 (with R2 recently released).
I would invite those seeking more information about the subjects examined in my posts, and those not examined, to consult the literature published by Microsoft online.

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