ShadowofReason
New member
Hi.
One of our clients was expecting an email, but the server rejected it for the following reason:
2019-12-30 10:16:02 SPFCheck: 1.2.3.4 is not allowed to send mail from mailserver.tld: Please see http://www.open-spf.org/[email protected]&ip=1.2.3.4&receiver=our.server.tld : Reason: mechanism
My first thought was that their SPF record was messed up but upon doing a quick <dig -t TXT mailserver.tld> I got this response:
"v=spf1 mx a:external.mailserver.tld ip4:7.8.9.0/28 include:spf.protection.outlook.com -all"
So here's the problem.
The spam blocker does check for "ip4:1.2.3.4" ( which isn't listed in the SPF as written ), but it doesn't check "a:external.mailserver.tld" (which translates to 1.2.3.4).
Is it a configuration issue or is it an actual bug? According to RFC "a:subdomain.domain.tld" should be enough aswell.
I had to hide actual IP addresses and domain names due to NDA reasons, hope the problem is clearly explained tho.
Thanks in advance!
One of our clients was expecting an email, but the server rejected it for the following reason:
2019-12-30 10:16:02 SPFCheck: 1.2.3.4 is not allowed to send mail from mailserver.tld: Please see http://www.open-spf.org/[email protected]&ip=1.2.3.4&receiver=our.server.tld : Reason: mechanism
My first thought was that their SPF record was messed up but upon doing a quick <dig -t TXT mailserver.tld> I got this response:
"v=spf1 mx a:external.mailserver.tld ip4:7.8.9.0/28 include:spf.protection.outlook.com -all"
So here's the problem.
The spam blocker does check for "ip4:1.2.3.4" ( which isn't listed in the SPF as written ), but it doesn't check "a:external.mailserver.tld" (which translates to 1.2.3.4).
Is it a configuration issue or is it an actual bug? According to RFC "a:subdomain.domain.tld" should be enough aswell.
I had to hide actual IP addresses and domain names due to NDA reasons, hope the problem is clearly explained tho.
Thanks in advance!