Relaying SASL authentication

Hello,

We have an incoming relay server for our domain. This relay server
receives all the email directed to us, and redirects them to the
corresponding subdomain mail server. This is also the only server you
can connect to its 25 from outside our network (with the corresponding
firewall rules).

The problem we have is that now we have a subdomain we are the primary
MX and their users need to send messages from outside our network. We
have configured SASL authentication in this server against an LDAP
directory to authenticate users of one domain. But the users of the
other domain are not in the LDAP directory, they are define locally in
ther subdomain mail server.

The question is if there is any way to configure SASL to authenticate
against the LDAP directory for the users of the first domain and to
proxy (or something similar) the SASL authentication to the users of the
other domain.

Other suggestions are welcome.

Thank you in advance.
=09
--=20
Angel L. Mateo Mart=EDnez
Secci=F3n de Telem=E1tica
=C1rea de Tecnolog=EDas de la Informaci=F3n _o)
y las Comunicaciones Aplicadas (ATICA) / \\
http://www.um.es/atica _(___V
Tfo: 968367590
Fax: 968398337