Photos in Digest
The Digest version can display photos for each person that has posted a message to the list. These photos are pulled from Gravatar, a free service that is used mainly by bloggers.
The photo is useful for helping to remember people met at in-person conferences, meetings, etc.
Digest with Photos
If mailing list members have not posted their picture or avatar at Gravatar, a blank silhouette is shown.
Gravatar is Free
This is a free service for website owners, developers, and users. A WordPress.com account is required in order to utilize the Gravatar service.
For more information, go to http://en.gravatar.com/support/how-to-sign-up/ to sign up.
The email address used with a Gravatar account must match the address used on the mail-com mailing list.
Once the Gravatar account is created, the next Digest email will include any new photos.