I mentioned SPF a few weeks ago in an early blog on this site. SPF, or Sender Policy Framework, is a technology that allows for a reverse DNS lookup of mail servers.
In the current way that the domain name system (DNS) works you have a record called an MX (Mail eXchange) record. This record points to one or more mail servers that accept email for that domain. You can also place a priority on each MX record setting up the order in which email servers should be tried.
SPF adds a new record as a TXT record in DNS. This record primarily describes where email from a given domain can come from. So while the MX record is the way for the sending email server to validate where to send the email to a SPF record is a way for the receiving email server to validate where the email is coming from.
So what does this do for spam and viruses?
In my humble opinion SPF has the ability to cut spam and viruses by 80% to 90% or more.
How many spam messages do you get from an email address that is not valid? All of these would go away unless they were sent through the correct email server for that domain name.
How many viruses forge email headers and look like they can from a friend of yours, even though they really came from a computer someone else in the world? These would all go away.
From a business perspective, this would eliminate all of the bank card scams, where the email looks like an official correspondence from citibank or even ebay but they are really scammers trying to get your credit card data.
So what is it going to take to make this a reality? It’s going to take the support of everyone who is in the tech field controlling any email server and/or the people who control their projects. The more people who publish SPF records and the more people who add SPF support to their incoming mail servers the faster this will become a reality.
Just think of all the time and money you and your company could save if you didn’t have to worry about 80% of the spam or viruses anymore. It’s worth it, it just needs to be done.
For more information about SPF check out http://spf.pobox.com/