Digital Marketing

Do SPF Records apply to subdomains?

You need to have separate SPF records for each subdomain you wish to send mail from.

This makes sense - a subdomain may very well be in a different geographical location which will have a very different SPF definition.

The 'include:' directive for SPF may be used to provide all subdomains with the same entries. For example, on the SPF record for subdomain enter ''. In this fashion whenever you update the definition for your subdomains will automatically pick up the updated values.

If a subdomain is created as a CNAME record, the SPF record is the one for the domain it points to, e.g. is a CNAME of, the SPF a mail server will get when it looks up is in the DNS record for This is the same if the CNAME record says =>, so your TXT record would need to be othersub, not sub.

This is in contrast to DKIM, which needs a separate TXT record for the public key, even if your subdomain is a CNAME.


Popular posts from this blog