GW6.5 as POP3 Client

I have GW6.5 and am using it to connect via POP3 to a third party mail
server (i think its NetScape Messenger). The user accounts on the server
are set up like joe.b.anthony@domain.com - the problem is that when you
try to send mail to someone from GW (like the to the example address
listed above), the GW client will attempt to send the mail to
joe@domain.com rather then the full address. Is there some way to make
GW use the full address that is typed in?

NOTE: In outlook, sending mail to addresses like this have worked fine,
so I'm assuming its not on the server end, but rather GroupWise

Thanks,
Joe