Identicons (avatars, sigils) are meant to give a recognizable image that identifies specified entity (e.g. contact person), like photos. So, when a contact photo is not available we could still have a kind of nice image that is unique for every contact (email address).
I just committed the identicon plugin for Roundcube that implements this. So, if a contact does not have a photo specified, instead of the boring “gray person” image, you’ll see a nice icon image. The icon is unique for every email address.
Figure 1. Identicon in mail preview.
There are some libraries that implement this identicon generation algorithm. However, as it’s really simple I did it by my own. I didn’t really care to get icons identical with those from Github. If you care, send me a pull request.
The plugin can be found here. It requires PHP-GD extension and it should work with all recent versions of Roundcube including 1.2, 1.1 and 1.0.
Also note there’s already the gravatar plugin, but it uses an external service, which may not be acceptable in some cases, even if you run the service by your own. Wanted a simpler solution? Now you have it.
Figure 2. Identicon in contact information frame.