exim, different users and safe passwords?

[Strowi]

hi everybody,

i'm about to install a mailserver on our home-router-box. Since i think postfix is a little over-the-top for our P3-650mhz,128MB i am looking into exim ríght now, looks good.

But one thing i couldn't find: Is it possible to allow each user on our LAN to add a new Mail-Account to receive a new @gmx.de-Account _without_ having access to the other users passes/accounts? This way everybody can add as many accounts as he wants without worring about security of his passes...

Thx!