XFOR: Configuring Internet Mail Service for POP3 Clients

When using Microsoft Exchange Server version 5.0 or version 5.5, Post Office Protocol (POP3) protocol you can allow any POP e-mail client to connect to an Exchange Server computer and read messages from an Exchange Server Inbox. The POP3 protocol is designed to work in conjunction with the Internet Mail Service to support both sending and receiving mail.

If mail from a POP3 client is to be routed to recipients outside the Microsoft Exchange Server organization, you must configure the Internet Mail Service to reroute mail.

Use the following procedure to configure the Internet Mail Service for POP3 clients.

NOTE: If the Internet Mail Service was not configured to reroute incoming Simple Mail Transfer Protocol (SMTP) mail, you may receive a non-delivery report (NDR) for any messages submitted by POP3 clients to recipients outside the organization. To resolve the problem, configure the Internet Mail Service, and re-send the messages.

1. In the Exchange Server Administrator window, double-click the Internet Mail Service you want to configure.
2. Click the Routing tab.
3. Select Reroute Incoming SMTP Mail (required for POP3 support).
4. Click Add.
5. Type the SMTP domain name of your organization, and select Should Be Accepted As "Inbound".
6. Click OK.
7. Stop and restart the Internet Mail Service.