Firewall Wizards mailing list archives

Remote Mail Users


From: Greg Taylor <gtaylor () ntyne demon co uk>
Date: Tue, 23 Sep 1997 11:45:35 GMT

Hi,

Can I please submit a problem which has had me confused for weeks?

I have an internal network of mail users using MS exchange with an exchange 
server.  The SMTP connector of this goes via a Gauntlet firewall to the Internet 
(or at least will do when we have completed configuration!)

I also have a community of remote users who need to send mail by attachments to 
the main server.  The intention (for strong security reasons) is for them to use 
Smartgate providing encrytion of the link.  They will also only be allowed SMTP 
via the firewall.

THE PROBLEM - Exchange server can accept SMTP mail but cannot operate as an SMTP 
post-office.  I DO NOT WANT to open any further ports in the firewall.  I have 
had suggested a POP3 server within the firewall with that connected to the SMTP 
connector of exchange but that means that any user who could be both on the 
internal network and who could work from home on a laptop would be a user on two 
main systems.  How do I ensure that whichever system they log in they get the 
same mail?  At the worst case I could accept a system where the mail is sent to 
both but can this even be improved on?

Horrible picture follows:

Internet ----> Firewall ----> POP3 server -----> Exchange Server ----> user
                  |
              Shiva Modem stack
                  |
             Remote laptop user.

The firewall permits only ports 25 and 80.

The preference would be to have the remote users also using exchange client set 
to dialup networking although I beleive(?) exchange is not POP3 compliant.

Any ideas please?  I am completely stuck over this one!   :-(

Greg

May you live in interesting times.  (Ancient Chinese curse)

Greg Taylor MBCS, FIAP                             gtaylor () ntyne demon co uk
Open Systems Programme Leader
North Tyneside Council



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