Global Alert / email problem

We're running 5.0 and use several global alerts both
standard and customized. We find that some PC's will send
them and some won't. It generates the same error message as
you would see if Outlook wasn't open and you tried to send one.
(Unable to access Mail server)
They just won't send them. I can send them on my PC which uses
Windows 98. My boss can't and he's got Windows 95. Everyone
here uses Outlook (and yes it is launched when sending
the global alert!). Could it be a simple matter of adding
a .dll or .pst file in the system folder? Thanks - Kevon
If using email respond to: (khuntley@a...)