NAT authentication question

[markt]

We have http, pop3 and SMTP all via proxy - we also use
teminal services & VNC out through wingate, this goes via NAT.

Is there a way to force authentication before a NAT connection is created?
We do not 'currently' use WGIC, only java.

The problem arose following a laptop users picking up a keylogger app
that connected out TCP via NAT.

Help is appreciated.

Mark

[markt]

Could anyone point me in the right direction please?

Thanks in advance.

Mark.