Converted esisting Email security to Mailflow with MS365

We've successfully setup Mailflow for our MS365 domain. We used the "copy existing MS365 Domains and Policies" and confirmed.

Mailflow seems to be working correctly after testing. All looking good. However I am curious what to do with the existing DNS settings that we've configured at our 3rd party DNS hosting for the old situation.

What happens to existing created records that are still pointing to the SOphos Hydra servers?

- MX

- SPF 

DO these servers need to be removed and MX reverted back to the initlal MS365 DNS from Microsoft?

I  have a hard time finding out if anything in DNS config is neccesary to revert or not.

Parents Reply
  • those are likely servers that have cached the old mx and or are configured directly pointing to the old record. They should clear up over time, if not you will need to investigate and if they are servers/applications under your control change the mail host or smarthost entry. If they are from external senders they will update cache over the next couple days, although it should be sooner propagation can take up to 72 hours for some DNS providers.