Strange SPF - Exchange Email issue
Posted on 2014-03-27
Hi all, I'm having an issue with an SPF record on an exchange server that's confusing me. We have all the correct DNS settings set up for a mail server "mail.domain.com". We have a txt record with:
v=spf1 mx -all
Which should mean it will allow mail from the mx server (which is "mail.domain.com"), yet when we send email to a certain client (who is outside the network), their email server rejects it with a SPF record error: SPF unauthorized mail is prohibited.
someserver.secureserver.net gave this error:
SPF unauthorized mail is prohibited
(that's the receiving server)
It sends the original headers back with the email and it says:
Generating server: EXCHANGE.domain.local
someserver.secureserver.net #550 5.7.1 SPF unauthorized mail is prohibited.
Received: from EXCHANGE.domain.local (192.168.1.21) by EXCHANGE.domain.local
(instead of the outside domain)
Also, another part says
Which is their internal IP address that I obviously can't add to the SPF record. I'm guessing this is somehow the problem, the external mail server is somehow getting the internal IP address of the mail server, and it's rejecting it due to the spf?
Does anyone know might be wrong with the setup?