RE: Exchange Picking Up Email

Douglas Warren ( dwarren@alpha.NetUSA.Net )
Thu, 18 Dec 1997 13:02:14 -0500 (EST)

On Thu, 18 Dec 1997, George G. Stossel wrote:
> I'm not sure I fully understand where your at and were you want to go,
> but we are using Exchange as the mail server for our small ISP operation
> and it works.

Let me try again, at our end we are running on a UNIX based system and
one of our customers has a large internal LAN (approx 500 users.) And
they wish to use Exchange Server to talk with their local desktop machines
to send and receive email. That is, mail is sent to the exchange server
from their desktop then out to the internet, incoming mail goes to the
exchange server where the desktops pick it up from POP3. Because this is
a dialup connection and not a dedicated connection, I don't like the
idea of using SMTP to talk beween OUR mail server and the exchange server.
What happens currently is someone tries to mail them, they're not connected
at that moment, so it goes to our mail server. (We are an MX server for
them, but their exchange server is has a lower MX record.) When we get
mail for them, we hold it trying to send it to their server every 30
minutes or so. The upshot of this is that if they connect via Dialup
networking 1 second after we try to send them mail, they will need to
stay online for 30-35 minutes in order for that mail to get to them!
What I would *LIKE* to do is to throw *ALL* mail for their domain into
a flat file. Then have *SOME* program (Wether exchange itself, a module
for it, or a 3rd party piece of software.) come along and authenticate
itself via either POP3 or IMAP4, and collect this mail. Then, it should
turn around and internally offer it to Exchange as a normal SMTP connection,
so that exchange is nonethewiser as to where the mail came from. What
atleast one of these customers have been doing is having an individual
assigned to read all mail that comes into the company then bounce it to
the right individual, which isn't a scaleable nor acceptable policy.

> On the server side, you configure Internet Mail Connector (IMC) to
> retrieve mail for all domain names that you are hosting mail service
> for. If you have a dedicated connection then the DNS entries for the
> domains have an MX record that points to your server. If you have to
> dial an ISP to retrieve mail then IMC is set up differently.

How is the IMC set up in a case like this? We currently have the MX
records pointing to the dialup machine and our own.

---|Douglas ``Wildcat'' Warren |Email:|  Jura gur tbireazrag|Network/Security Consultant|Phone: (516) 543-0234    | bhgynjf Pelcgbtencul,|President of SBCS a chapter|  Fax: (516) 543-0274    |  bayl pevzvanyf jvyy|of the ACM.                |  PGP: finger dwarren    |     unir cevinpl