Email server+network architecture

[dataclaus1 () hushmail com]

-----BEGIN PGP SIGNED MESSAGE-----

Fellow list folk:

Situation:  My company is very restrictive on internet and email use.  Only select users are allowed external use, and 
fewer still have unrestricted net access.  Communications (email) with 'customer data' are not permitted outside the 
corporate perimter, including the DMZ.  We do not wish to have all of our users able to pop3/smtp outside our corporate 
perimeter, even to the DMZ.  We want an email schema as listed below:

Inside<->Inside:      all users
Inside<->Outside:     Only those designated by management

Currently external mail is hosted by our ISP but saving that money would be nice.

Thinking about a topology-based solution presents the following:

I can set up a 'corporate' mail server Inside (and no external linkage)without much trouble.  But then the 
external-permitted people have to manage two accounts, one for inside and one for external mail (since those having 
external mail are some of the least computer savvy, this is not the best answer).

Research indicates that putting a mail server Inside and then configuring a conduit through our firewall is the least 
preferable option, as compromise would allow Inside access.

We don't want to place the server in the DMZ because then we'd have to permit smtp/POP3 to all users outside, and this 
does not meet the 'no customer data Outside' criteria.

It seems I'm between a rock and a hard place.  Have I missed something?  Encryption may be an option, but is not 
implemented currently and we would still reqire a policy change (read slow Board proposal/approval process) before this 
would be a solution for a DMZ mail server.

Any suggestions as to a topology or other creative solution that would work would be greatly appreciated.

-----BEGIN PGP SIGNATURE-----
Version: Hush 2.2 (Java)
Note: This signature can be verified at https://www.hushtools.com/verify

wl8EARECAB8FAj4jF4YYHGRhdGFjbGF1czFAaHVzaG1haWwuY29tAAoJEMX8YnuPyP0P
y+wAnjEdzxS5cU76zQvHH22xhxv9JV0aAJ4zLBIJTQyaNscrlpSRKzId947SMw==
=VmcP
-----END PGP SIGNATURE-----




Concerned about your privacy? Follow this link to get
FREE encrypted email: https://www.hushmail.com/?l=2 

Big $$$ to be made with the HushMail Affiliate Program: 
https://www.hushmail.com/about.php?subloc=affiliate&l=427