This extension lets Mozilla Thunderbird display 'face' images in the message header section of e-mails and newsgroup messages. These face images are intended to represent the sender, in the form of photos, cartoons, logos and so on. MessageFaces supports the following Face types:

Type Description Supported
Face header Color PNG file embedded in the mail itself (specification) Display & Set
X-Face header Black-and-white image embedded in the mail itself. Display only; optional 'Globally recognized avatar' retrieved online from a central service. Display only; optional
Local images Any image in a directory of your choice. Display only; optional
Face URLs An image loaded from a web address specified in the mail (possible privacy and security risk!) Display only; optional
Picons Short for 'personal icons.' Images used to represent users and domains on the net.
Display only; optional
Contact Photo Displays the contact photo for the sender (contained in the address book)
Display only; optional
Google+ Photo Displays the Google+ photo for the sender (requires gContactSync extension)
Display only; optional

Download / Installation

Download MessageFaces 1.3.1 for SeaMonkey 2.0 to (released 2020-12-14)
Installation: Save the XPI file somewhere on your hard drive. Then, go to Tools->Extensions, click the "Install" button, and select the messagefaces1_3_1.xpi file.
On modern versions of Mozilla, you can just drag the .xpi into the browser window.

A screenshot of the Thunderbird message header pane with a face image on the right side
newscheck window
mailcheck window

Valid HTML 4.01!