The Postmaster system is intended to take an e-mail as input and then send it out as instant messages to multiple avatars. It is able to filter e-mails to different groups of avatars depending on the subject of the e-mail. You can filter based on exact subject matches or partial subject matches.
The Postmaster is designed to accept e-mail from outside of Second Life (external) and from other Second Life objects (internal). E-mail from other Second Life objects will automatically have the Second Life header information stripped from the message before sending.
Also included is a built-in avatar scanner which allows you to detect the avatar keys of up to 16 avatars within 30 meters of the Postmaster.