While helping one of our customers figure out how to do an email auto-responder, I ran into an interesting way to do it with either Google Apps or a regular Gmail account. The following article outlines the process of setting it up:
Basically, it allows you to take the “canned response” feature available in Google Labs, which is pretty useful itself, and set up a filter to have it automatically send an email response if an incoming message meets a certain criteria. This makes for a very flexible email responder. It means you could set up an email alias to have people send messages, and then use a particular canned response to automatically return an email reply only to them. Or you could set up a particular reply in response to certain key words in an incoming message. Anything you can use a filter for in Gmail can also be used to send back a canned response.
The only drawback I found was that you can’t set it to send from any specific email address even though you may have other accounts associated with your Gmail account. It will only send the automatic message as being from the main account associated with that mailbox. But if you can live with that, then it’s a great solution.
(syndicated from blog.netcrafters.com)