Mail Domain Only

I’m being asked to make a subdomain for outbound mail purposes only. There will be no email received by this domain - it is send only to our cloud based vendor. It /appears/ to be for validating DMARC (SPF/DKIM) against for our external vendor. We have ‘acme. com’. We’re being asked to create ‘ap. acme. com’. The idea being that our staff will create an email from ‘[email protected] com’ and send an invoice to ‘[email protected] acme. com’. Never leaving our mail server except to be sent to the mail server at ‘ap. acme. com’. I feel so sophomoric asking about how to set this up. It feels it should be fairly academic. What minimum records do I need to create to support a send only domain that validates for DMARC?

For a send only domain, you need SPF, DKIM and DMARC records.

1 Like

Agree, thank you. What about A, CNAME, and MX? I don’t have an IP for an A record. This is where my brain is getting stuck. And making a CNAME to ‘acme. com’ doesn’t seem right.

You don’t need an A or CNAME record because you are not resolving anything. You don’t need a MX record because you are not receiving email.

1 Like

And that makes sense. I’m trying to put a round peg in a square hole. The vendor’s documentation asks for the subdomain, so I’m all fired up to make SOME record for that domain! Yes, I overthink too much sometimes!

Thanks!

Well you could create a null MX record https://tools.ietf.org/id/draft-delany-nullmx-02.html#:~:text=4.-,The%20NULL%20MX%20Resource%20Record,mail%20exchanger%20for%20a%20domain.

1 Like

This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.