Linux servers cannot send the password because they cannot retrieve the password; it's stored in a one-way encode.
You can't write a program that will automatically change the password for any user that requests it, and then email the information to the email address on file for the user because the user won't be able to log in to get it.
You could do something if DA required each user to have another email address at another server, but it doesn't (and probably shouldn't for lots of other reasons), so you'll have to have your own method of recognizing the user (do you know his/her voice) and changing it manually.
Jeff