Besides mailing lists, Lyris also does auto-responders and "mail robots".
An autoresponder is an email address which sends back a document when someone writes to it. For example, you can set up a "prices@acme.com" auto-responder which sends back a price sheet to whoever sends mail to it.
A "mail robot" is an email address which responds to commands by sending email back. You define the words the Robot looks for, and how it responds. For example, you can have a "robot@acme.com" email address. If someone sends the words "send price sheet" you can have it look for the words "send price sheet" and respond by mailing a price sheet back. You can define as many "action phrases" as you like, each with its own response document.