Gmail users can see who digitally signed an e-mail by clicking &34'show details&34' at the top of the message.

Google announced today that it is making it easy for organizations using Google Apps to authenticate outgoing mail so that recipients can rest assured that the messages are really from them and aren't spam.

Administrators of all editions of Google Apps can enable the DomainKeys Identified Mail technology for outgoing mail in the "Advanced Tools" tab of the control panel by checking several boxes. Gmail has supported e-mail signing standards since its inception in 2004, but implementation required more configuration and resources than that.

Functionally, this means fewer legitimate e-mail messages will be blocked by spam filters.

To protect Gmail users directly from phishing attempts using the eBay and PayPal names Google worked with those companies a few years ago to authenticate e-mail coming from them and block all unsigned messages.

More information is included in a post on the Google Enterprise Blog.