|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 aprs.fi, and correctly classify those as junk. It also might help GMail figure out that the registration confirmation and password reset emails sent out by aprs.fi 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.