sending smtp mail from behind a cisco router to an exchange server

[gojoerun]

This might be extensive...i'm looking for some information to clarify a problem...

I have a situation where a router separates two subnets. On one side is a VMS (or Unix) server with no SMTP server. On the server is an application which can send email alerts. On the other side of the router is an Exchange 2000 server. The email alerts from the VMS server need to reach it's destination on the Exchange server. I am thinking that the cisco router need to be configured to allow SMTP through. My question is does the sending application need to complete SMTP acknowledgement before the message can be place in the MTA of the Exchange server ? or does it not occure until it's in the MTA ?

I propose to put the IP address of the router(on the VMS side) for the mail server destination to point to the gateway (router) in a host file and configure the router to forward SMTP mail to the IP address of the exchange server on the other side. I am hoping that the "HELO(EHLO), OK" communication will complete properly. My objective to to get mail flow from the VMS to the Exchange server without having to introduce a SMTP server on the VSM side.

This is all to confusing ...I hope it makes some sense to someone who can clarify if I'm on the right track with my thinking. Any Routing/SMTP/DNS experts out there ??

Thanks in advance !

Joe

 

[ChrisAC]

Are you doing any filtering on that router? Why not just have the Unix server send mail directly to the Exchange server via the router, instead of having the router do port forwarding.

Chris.


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Chris Andrew, CCNA, CCSA
chris@iproute.co.uk
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