exim4 and mobile users

[Enrique Morfin <enriquemorfin@yahoo.com>]

Hi!

I have a mail server, using exim4, pop3s and a webmail
interface (using php).

I have some mobile users, using win xp and win 2000,
and they use outlook express, eudora and netscape
mail.

Inside the network everithing works fine.

The problem is when the users go out. They can get
their mail, but can't send mail. (And they refuse to
use the webmail (and they are the bosses))

The relay is closed (except my own network).

Is there a way to autenticate those users, so they can
send mail when they are out of our net?

Thanks.

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