Sender Policy Framework (SPF) is an email validation system that blocks spam in the form of spoofing. “Spoofers” commit mail fraud by sending mail from what appear to be trusted addresses in order to gain sensitive information. An administrator can choose which hosts may use a given domain by creating an SPF record in the public Domain Name System (DNS). The DNS can then be used to verify that email from a given domain is sent from a host approved by the domain’s administrators.

Why It Is Needed

The single advantage of publishing an SPF Record is that Spammers and Phishers will not be able to forge the email sending domain. Spammers will not be able to pretend that they are sending mails from your domain name. If they do, that mail will be caught by the Anti-Spam systems of the respective ISPs and the mail will land in the Junk or Spam folder.

Thus by publishing an SPF record you are making your domain spoof-proof.

So Let’s Get It

It’s very simple. The SPF Record looks something like this:

“v=spf1 a mx -all”

In the SPF Record, you can determine which IP addresses and domains can send mails on behalf of your domain, preventing spoofing.

Let’s say you are a client of Benchmark Email and you are sending emails to your customers through the Benchmark Email platform. For better deliverability, you need to explicitly allow Benchmark Email to send mails to your customers on your behalf.

The SPF record for yourwebdomain.com should go in your DNS manager something like this:

yourwebdomain.com IN TXT “v=spf1 a mx ip4:1.2.3.4 include:thirdpartyespdomain.com -all”

where,

1.2.3.4 = the IP Address of the your mail server or 3rd party ESP like Benchmark Email and thirdpartyespdomain.com = the domain of the 3rd party ESP like Benchmark Email or their relay mail server’s domain name.

You can get great help from the links given here:
– http://www.openspf.org/SPF_Record_Syntax
– http://www.openspf.org/FAQ

How to Test

Once you have published your SPF record as a DNS TXT record, you can test it by visiting the given links:
– http://www.mxtoolbox.com/spf.aspx
– http://www.kitterman.com/spf/validate.html

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by Benchmark Team