Question : Exchange 5.5 - How to setup a smarthost to provide Pop3 access, without mailboxes

We have a site in a foreign country that only allows the use of dialup connection – because of rules in that country, the IP address assigned to that server is a private, non routable IP.   VPN traffic is also not allowed in this traffic, and VPN ports are blocked at the ISP.

This site is set up as a stand alone domain running NT 4.0 and Exchange 5.5.  For that site to retrieve email, we have their MX record pointing to one of our exchange servers here in the US.  That exchange server has an SMTP routing rule that forwards messages for that particular email domain to an old Mac OSMail server which acts as a POP3 smarthost.  Individual mailboxes are not set up on the smart host.
 
The Exchange Server overseas connects to the internet via dialup, then collects their mail using a Pop3 connector called Popcon.  

I’ve read a lot about using ETRN, but that requires the overseas Exchange server to get the same IP every time it dials up, and it gets a public routable IP.  ETRN is not possible in this scenario.

I need to find a way to migrate the email hosting off of the Mac server onto an Exchange 5.5 server here at HQ.  I’ve researched quite a bit but cannot find anything about setting up a POP3 Smarthost on Exchange 5.5  We'd like to just host the mail on our exchange server (without
creating mail boxes), then change the dns host record pointing to the
mac server so that it points to one of our exchanger servers.  

Any help would be appreciated!

Answer : Exchange 5.5 - How to setup a smarthost to provide Pop3 access, without mailboxes

Sorry, but I don't think Exchange 5.5 can not do it. Even the newer Exchange 2000 and 2003 do not have the required "catch-all" capability but at least there are inexpensive 3rd party additions that do this.
If you can switch to Exchange 2000 or 2003 on your side (you can stay with 5.5 on the remove server over in that foreign country) this would be the way to do it:
Use Exchange 2000 or 2003 together with CSCatchAll (http://www.christensen-software.com/cscatchall.htm) as catch-all extension. This would allow you to receive all email for a given domain into a single Exchange 2000 or 2003 mailbox. POPcon can then download email from that mailbox via POP3 and find out about the correct recipient by examining the "Delivered-To" mail header field (POPcon does this by default if you configure it to download mail from a catch-all account) and forward it to that recipient on the foreign machine.

But unfortunately I don't know about any catch-all extension to Exchange 5.5 and this seems to be the crucial part here if you need to stay with 5.5.

- Claus