AFAIK there is no RFC or other standard to retrieve an avatar (image/icon) from an email address.
I think this would be a great feature.
One possible solution:
Get avatar via DNS
- user enters his email address.
- The domain belonging to this email adress DNS gets asked: Avatar for "foo@example.com"
- DNS replies: Get image from URL. For example:
http://example.com/foo.png
Questions
- Is there already a RFC or other standard?
- Why is there no such standard yet?
- How to get it come true?
I know that Gravatar exists. But AFAIK it is not a standard.