Google Mail Servers and False Positive Spam

Last year, we posted an article about using DNS SPF records to help reduce the incidence of spam false positives. I wanted to update the info with a recent discovery that can help any of you using Google Apps as your email service for your personal or corporate domain name.

We have a client whose application was subject to false positives when emails were sent to other users with Gmail or Google Apps-hosted accounts. The client is using the Google Apps email service for both sending and receiving emails. Per spec, they have a valid SPF record that includes an “MX” definition for Google’s mail servers, authorizing Google to send emails on their behalf. However, we noticed that emails sent from the domain to other Google emails were “soft failing” — in other words, Google was failing emails originating from their own servers.

The fix is easy — be sure your SPF record has “include:_spf.google.com”; example:

v=spf1 a include:_spf.google.com ~all

Hope that helps!