Exchange 2007 and external Mail Servers

Question

This may be a dumb question, but i'll ask anyway:

We have existing internet mail accounts provided by an ISP which we pickup using POP3 mail in outlook.

We want to deploy Exchange 2007 internally, but initially keep mail services running with the ISP but use Exchange as the conduit for mail coming in and out of our building (so we can use activesync).

Now i know its possible for smtp to be sent from exchange to the ISP mail server but how do we pick up the mail from the ISP into exchange? Is this possible with POP3 and the multiple different usernames and passwords that exist for current e-mail accounts? I appreciate that ultimately mail needs to go directly to exchange but we aren't yet ready for that.

Thanks in advance

Answer 1

Downloading mail from a POP server is not natively supported in Exchange 2007. Exchange that comes with Small Business Server does have support for downloading email via POP from different servers and for multiple users. There are third party applications you can use, but there is a cost involved. One of these third party add-ons is MAPILab POP3 Connector for Exchange 2007.

Answer 2

Francois Wolmarans answer is absolutely right (and I'm upvoting it). There's no native "download POP3 and jam it into Exchange" functionality in Exchange 2007. You can use third party software to perform this function (I've successfully used the cygwin distribution of fetchmail running as a "Scheduled Task" on a Windows server...) or, alternatively, you can continue what you're already doing-- using the POP3 client in each Outlook client to download email and jam it into the user's mailbox.

Basically, as you establish a mailbox for each user you'll need to create an Exchange mailbox, import their existing .PST into the Exchange mailbox, and change the default message delivery location in their MAPI profile from the PST (which you'll ultimately disuse and delete) to their Exchange mailbox.

You can allow Outlook's SMTP client to send out messages or you can use Exchange. You can control this behaviour by changing the order of the accounts in the "E-Mail Accounts" properites. Personally, I'd only allow my Exchange Server computer access to the Internet via TCP port 25, and force all clients to send email via Exchange. (If all your clients are already configured to send email directly out to the 'net this poses a bit of a problem during the migation, but it's a good goal to shoot for by the end of the migration.) This prevents malicious software or attackers from sending email to the 'net w/o having credentials to have Exchange do the relaying for them.

Finally, you'll need to configure your domain in Exchange as an internal relay domain so that your users who have been migrated to Exchange can still send email to un-migrated users via the ISP's mail server (assuming you're not migrating everybody on one fell swoop). (That article is SBS-oriented, but it absolutely applies to non-SBS Exchange installs where you're maintaining existing POP3 outside on an ISP but transitioning to internal Exchange...)