ISA Server for Microsoft Exchange

[Connie Sadler <csadler11 () GMAIL COM>]

I am told that we need an ISA Server for Microsoft Exchange. I am asking for
the Reader's Digest condensed "english" explanation, but I am having a hard
time getting it.  :)  Can anyone here offer an explanation that will help me
to create a business case for this - for a non-technical audience? There is
a lot of info on the web, but nothing pops out as useful. I need a
translation from techno-speak to executive business need.

Thanks!

Connie Sadler
CISO, Lucile Packard Children's Hospital at Stanford