Exchange 2003, Forwarding External Mail on Same Domain

[OutToLunch]

Can I pick an Exchange guru's brain for a minute?

Is there any way, in Exchange 2003, to forward mail for *specific recipients* on the same domain to an external mail server? I know it is possible to set it to forward *all* unresolved mail but that creates issues with our catch all address...

To explain further - using Exchange 2003 with POP connectors only and a single catchall@ address for our main site, Exchange is picking this up from the ISP. There are a few users who are based off site and have their own specific POP3 mailbox on the ISPs mailserver - internal users cannot currently send mail to them unless I set up forwarding for unresolved recipients. The problem arises because of the use of a catchall address - any spam to unrecognised addresses is downloaded, then forwarded immediately back to the ISP, lands in the catchall mailbox, is downloaded, then forwarded... ad infintum.

What I'd like to set up is some way of forwarding say bob@mydomain.com to the ISP where it will land in a specific box and get out of the loop, whilst spam would be bounced correctly.

Any ideas? I know the setup is not ideal, but I had no part in the creation of it, and I'm stuck with it now, so I have to do the best I can with what I've got!

Cheers,

Ben

[steve]

Just to clarify things in my mind (tell me if I've got it wrong)

catchall@myschool.com on a POP email

Downloaded into exchange (except pre specified offsite@ accounts)

Exchange splits the catchall incoming mail automatically to internal accounts
headteacher@myschool.com, reception@myschool.com, user@myschool.com, etc

The offsite POP3 mailboxes have the same domain for their accounts, offsite@myschool.com

Anything not split to accounts, inc spam, would sent back to catchall@ if unresolved forwarded.

OK now this is a bit (a lot) of a bodge and would be a pain for more that 10 offsite accounts. But if the external POP3 accounts share the same domain name, I can't think of another way to get the mail off site.

Check with you ISP, do the offsite accounts have and underlying alternative email address? offsite@myschool.ipsname.com

If not you'll have to setup some more POP3 accounts, these must allow you to auto forward incoming mail. Set 1 up for each offsite user, and set it to forward to their offsite account. (Yahoo mail i think offer this)

In active directory setup contacts for all the offiste users. Attach the related offsite email (either offsite@myschool.ipsname.com, or the auto forwarding).

This will allow your internal users to get emails to the users with POP3.

AD Contact -> offsite@myschool.ipsname.com (which would appear directly in offsite@myschool.com)

Or

AD Contact -> offsite@autoforward.pop.com -> offsite@myschool.com

Far from ideal but should work.

[Ric_]

@OutToLunch: Is there no option to have an external IP address on your Exchange box? DNS could then be set up correctly to fire all the mail at the Exchange server. You can then simply set the forwarding options in AD Users and Computers for the users who have POP3 mailboxes elsewhere.

[steve]

If you could get an external IP, then DNS / SMTP would be the way to go.

You could also then ditch the external POP accounts and use OWA.

Sometimes we have to live with what we have though :-)

[Ric_]

Another thought... they occur sometimes

If your ISP supports it, you could use .forward files to forward the mail for specific users at the ISP so that their mail never reaches your Exchange box and all unresolved mail can then be bounced.