I recently bought a subscription to Microsoft 365 Family. I already have a domain (ratana.info) that I would like to use. However it appeared that Microsoft was pushing hard for users to register their domains with GoDaddy. There was no directly way to connect your domain from a different registrar.

After searching around, I came across this Reddit post which showed how it can be done. Here’s the cleaned up steps.

Step 1 Find your mxRecordValue

  1. Log into outlook.com
  2. On the top right menu bar, click on the Diamond icon (Manage Premium). This will pop up a Settings window.
  3. Under “Premium” -> “Personalized email address”, click to add a domain
  4. Follow through until a new window pops up with GoDaddy page
  5. Note the URL. It should be something like this: https://domainconnect.godaddy.com/v2/domainTemplates/providers/outlook.com/services/personalizedoutlookemail/apply?mxRecordValue=111111111&state=xxxxxxxxx&redirect_url=https%3A%2F%2Foutlook.live.com/mail/LaunchDomainConnectNextStep.html
  6. Note the mxRecordValue and the number after
  7. Close the window

Step 2 Add DNS records

  1. Log into your registrar
  2. Add the following DNS records 
    Type   Name            Value
----------------------------------------------------------
CNAME  autodiscover    autodiscover.outlook.com
CNAME  _domainconnect  _domainconnect.gd.domaincontrol.com
TXT    @               v=spf1 include:outlook.com
TXT    _outlook        111111111
MX     @               111111111.pamx1.hotmail.com
  3. Replace 111111111 with the mxRecordValue’s value from Step 1

Step 3 Add customized address

  1. Wait a few minutes for the DNS records to propagate
  2. Log into outlook.com
  3. On the top right menu bar, click on the Diamond icon (Manage Premium).
  4. Under “Premium” -> “Personalized email address”, your domain should be linked.
  5. Add a new customized address.

Step 4 Set custom address as default From

  1. Log into outlook.com
  2. On the top right menu bar, click on the Diamond icon (Manage Premium).
  3. Under “Mail” -> “Sync email” -> “Set default From address, select your new custom address