Procmail auto-responder
A Sample autoresponder to send info when someone sends a message to user {at} rimasec(.)net.
Create a file in your home directory called .autoreply and put what you want sent out in there.
Then put the following text in the .procmailrc file thats in your home directory.
:0 h c
* !^FROM_DAEMON
* !^X-Loop: user {at} rimasec(.)net
* ^(To|Cc):.user {at} rimasec(.)net
| (formail -r -I"Precedence: junk" \
-A"X-Loop: user {at} rimasec(.)net" ; \
cat $HOME/.autoreply) | $SENDMAIL -t