Sunday, June 21, 2015

DKIM, SPF and assorted tricks to get through spam filters

Today I've set up DKIM (DomainKeys Identified Mail) on the servers and within the DNS zone. A week back I already set up the SPF (Sender Policy Framework) records in the DNS, and fixed the reverse DNS information for the IPv6 addresses used by to send out email.

Mike Mozart / Creative Commons / Via Flickr: jeepersmedia
In non-technical terms, this should help GMail and other services to figure out cases of others sending email (spam?) on behalf of, and correctly classify those as junk. It also might help GMail figure out that the registration confirmation and password reset emails sent out by are actually not spam.

It has been a rather persistent problem - GMail has consistently labeled the registration emails as spam, and people have been asking why they're not getting the emails. In all cases the mails have been found in the spam folder. We'll see if this helps!

Thank you to postfix and opendkim for making this a rather easy thing to get going.