Google announced today they have added the ability for Google Apps customers to sign outbound email using the DKIM (DomainKeys Identified Mail) standard.
You can set it up for your own Google Apps domain (if you are the domain admin) using these instructions.
It’s a simple process but the trickiest part can be creating the DNS TXT record (which contains your DKIM public key), depending on how you manage your DNS. If you are serving DNS directly via your registrar, Google has some specific instructions for popular domain hosts.
Checking your work
Here’s a quick tip how you can check to make sure you created the record properly and it is being served…
I launched a new WordPress blog for a client a few months ago and have been watching as comment spammers find the site and do what they do best, leave spam. As the first few spam comments started coming in I would flag them then manually copy/paste the source IPs and URLs to the built-in WordPress “Comment Blacklist“.
Over time I obviously started seeing some duplicates and I noticed bursts of spam from certain IPs or linking to specific spam URLs. I was curious to see what these top IPs and URLs were, as they would seem the best candidates to include in the blacklist.