Don't you just hate those auto-reply emails to mailing lists and such? Auto-replies are still important though, especially if you are on extended vacation leave and want people who are trying to contact you to be aware of it.

The Unix way to do this is through the vacation(1) command and formail or in my case procmail.

vacation(1) is smart in the sense that it only provides replies once, and keeps track of this in a .vacation.db file in your home directory. Your auto reply message is a plain text file also in your home directory as .vacation.msg

From: kaeru@inigo-tech.com (Khairil Yusof)
Subject: At the beach suckers!
Precedence: bulk

I asked that there would be no salt in the margerita.. but but
there is salt in it. 

I could burn this resort down you know.. sir.. sir.. 

The bulk header will be respected by mailing lists and the auto reply will not be sent.

For your procmail recipe, just add (check your paths) and username.

:0 c
| /usr/bin/vacation username

The c will tell it to continue and go on to other filters after it so you will have a copy of the original email, or forward it etc.

When you're back, just remove the files and procmail entry.