Sender Policy Framework (SPF) fights return-path address forgery and makes it easier to identify spoofs. This fairly new and easy to use technique is availble in Simple DNS Plus.

What is Sender Policy Framework (SPF) ?

SPF makes it easy for a domain, whether it's an ISP, a business, a school or a vanity domain, to say, "I only send mail from these machines. If any other machine claims that I'm sending mail from there, they're lying."

When an AOL user sends mail to you, an email server that belongs to AOL connects to an email server that belongs to you. AOL uses SPF to publish the addresses of its email servers. When the message comes in, your email servers can tell if the server on the other end of the connection belongs to AOL or not.

And that's it! SPF aims to prevent spammers from ruining other people's reputations. If they want to send spam, they should at least do it under their own name.

Find out more about SPF