Danger Will Robinson!

Remember - any script which is invoked in response to a received email AND has as one of its possible actions "send an email" should only be written if you have thought things through *very* carefully.

Why? Mail loop.
Send an email. Something happens (mail bounces? You get back a non-delivery message, which is a whole new message to process, so we send another mail. That bounces, so we get back a non-delivery message. Ooh - an incoming mail, I'll send a message. That bounces. Ouch.

Autoresponders are hard to write correctly if you don't have a reasonable amount of experience with email. There are also tools (the 'vacation' program on most unices) to help you do this right, anyway.

Ditto filtering incoming mail. Locking mail files is great fun and hard to do right. You can lose mail easily this way. Specialised programs like 'procmail' work very hard to do this right.

The insidious thing about the above is that you can do all the testing in the world and not show up any problems.

Then your autoresponder manages to get an email from another autoresponder and the world melts down.

Yours, a patronising, cynical, wizened, email bod