Strange email sending problem

Our cellphones (rom Centennial) have email capabilities.  To send an email
to the cellphone, you send it to xxxxxxxxxx@xxxxxxxxxxx where xxxxxxxxxx is
the phone number.

We can't send email to the cellphones from inside our office through the
iSeries.  I can't send to the cellphones from a PC in our office via
Outlook, nor can I do it with the SNDDST command.  The iSeries is our email
server.

I _can_, however, log on to my Verizon DSL email account in a web browser in
our office and send one.  I can do the same from my Comcast email account,
namely, send one in a web browser in our office.

Does anyone know why that might be? Is it an iSeries issue?  Router?
Firewall?  Encoding?  I can ping cwemail.com from a command line on the
iSeries and my PC.

Thanks for any suggestions where to start.

-- 
Jeff Crosby
Dilgard Frozen Foods, Inc.
P.O. Box 13369
Ft. Wayne, IN 46868-3369
260-422-7531

The opinions expressed are my own and not necessarily the opinion of my
company.  Unless I say so.