SPF records for multiple domains with same MX
Domain MX
–---------- --------------------
host1.com mail.host1.com
host2.net mail.host1.com
host3.org mail.host1.com
This is what I originally thought the TXT record for "host1.com" would look like:
__host1.com - v=spf1 a mx ptr ip4:xxx.xxx.xxx.xxx mx:mail.host1.com mx:host2.net mx:host3.org ?all
mail.host1.com - v=spf1 a ?all__
Mail would originate from each domain, but the MX are all "mail.host1.com".
Any input on the correct way of setting this up would be most helpful. I feel like I'm getting something backwards or putting unnecessary information in the records.
1 Reply
So if all host1.com email is going to be sent from the same host, you probably should pick just one mechanism to specify its IP. Which mechanism to use is up to you - I would choose whichever is most likely to stay constant over time and over all your domains.
For me, whenever I add a domain to my mailserver and that server is the only handler of both incoming and outgoing mail for that domain, I go with this: > v=spf1 mx -all