While Office 365 online documentation covers the set-up for a broad range of DNS providers, I recently performed set-up on the DNS manager provided by WordPress.com coupled to their commercial offer. While this scenario is not covered (yet) by Microsoft documentation it is fully functional.
As reminder, the following record types are currently required to operate your Office 365 tenant properly:
- TXT record for verification
- TXT record for spam protection
- MX record for mail routing
- CNAME records for various purposes
- SRV records for Skype for Business
While WordPress.com supports all the necessary record types, you will not be able to control their Time to Live and the configuration of SRV records is a little complex. Therefore, here is a quick drawing in order to map correctly information from your tenant to the WordPres.com form.
No need to worry about the non-configurable TTL, it is set to 3600 which fulfills the Office 365 requirement.
As usual with DNS, it may take from minutes to hour for the changes you applied at your DNS host to propagate to other DNS servers. Therefore, you might have to wait a while before Office 365 Admin Center considers your set-up as valid.