SenderFace

SenderFace is an add-on developed for Mozilla Thunderbird, which gives you the possibility to associate email senders with pictures in order to identify friends, co-workers and business partners easier. It has simple options that don't require extensive knowledge about Thunderbird configuration settings.

To install the extension, find the Tools -> Add-ons section of Thunderbird's to drag and drop the downloaded .xpi file over the main window of the email client.

Once an image is assigned to a contact, you will be able to view it in the area with header details (on the right), such as sender address, date, receivers, and subject. To do this, you can use the built-in file browser to locate photo files as well as enter the correct email address of the persons you want to assign them to.

There's no limit to the number of associations you can make, but it's only possible to assign one picture to one person at the same time. There are also options available for updating existing pictures by replacing them with new ones, as well as for removing them from the SenderFace Settings area.

The developer intended to enhance the functionality of this Thunderbird extension by integrating the option to add multiple email addresses per image, displaying a small picture in the message list and next to the Sender column, as well as to save the pictures in the file system instead of Thunderbird's preferences panel.

However, the project seems to be now discontinued and, unfortunately, it doesn't work with the latest Thunderbird editions, so you can only use SenderFace if you have an older Thunderbird version installed.