OIS Site Forum

Frustrated with unscrupulous spammers sending you SPAM email from your own domain? Have you had a message bounce back to you that you know you never sent? Are people accusing you of sending them SPAM? This technique, called email spoofing, is often used by malicious spammers to cover their tracks by falsifying the sender address. There is a way you can fight back and reduce the amount of SPAM coming into your own mailbox. The answer is to take advantage of something called the Sender Policy Framework (SPF)...and it won't cost you a thing other than spending a few mintues to add a DNS entry to your zone file. SPF can prevent sender address forgery by specifiying the IP addresses or hostnames of the email servers that are allowed to send email for your domain. Email servers that have SPF checking enabled, will query your DNS zone file for an SPF record, which is a text (TXT) record with a specific format. If the email server querying your SPF record finds that the email they received is not from an approved IP address or hostname specified in your SPF record, the querying email server can reject the message depending on how their policy is configured. The email servers we use here at OIS, will query for SPF records, which helps to reduce SPAM.

 To add your own SPF record, just login to your Control Panel and go into your DNS Zone Editor. Create a new TXT record with a format similar to this:

v=spf1 mx a:mail.example.com ~all

 http://www.openspf.org/ has a Wizard that will help you create a correctly formatted SPF record. You can copy/paste the results of the wizard's output to the TXT record in your DNS zone file that you are using for your SPF record.