[plug] checking for existence of an application

[Jon Miller]

Is there a way to check for the existence of the mail program in use.  I'm looking for a method that can state which mail program is active in a script.  It would probably be several "if" statements to check some of the more popular ones and the one that responds would be used in a variable.
Unfortunately using 'which postfix' or 'which sendmail'  would be of much use since both may be still installed on the server.

Thanks

Jon L. Miller, MCNE, CNS
Director/Sr Systems Consultant
MMT Networks Pty Ltd
http://www.mmtnetworks.com.au

"I don't know the key to success, but the key to failure
 is trying to please everybody." -Bill Cosby