The instructions below are for Exchange Server 2003. For other versions of Exchange see here.

You can link VPOP3 to Exchange Server, so that Exchange Server sends outgoing mail through VPOP3 and VPOP3 sends any incoming mail directly to Exchange Server.

You should first of all set up VPOP3 to send and receive Internet email as described in the online help.

As both VPOP3 and Exchange Server are on the same computer, you will need to change the TCP/IP port assignments for the SMTP service in Exchange Server.

1. On the Exchange Server computer go to Start → Programs → Microsoft Exchange → System Manager
2. Under Servers on the left side of the screen (on some configurations this may be under Administrative Group → First Administrative Group), choose the server name, then Protocols, then SMTP, then right-click Default SMTP Virtual Server and choose Properties
3. On the General tab, press the Advanced button.
4. Select the (All Unassigned) line, and press Edit…, In the TCP Port section enter a different number (larger than 1024), such as 5025 and press OK three times.

Now follow the instructions for VPOP3 and Exchange Server on different PCs below

Because both VPOP3 and Exchange Server are mail servers, they may both try to use the same TCP/IP ports which will lead to conflicts if they are both running on the same computer. This may happen with ports 110 (POP3), 143 (IMAP4) or 389 (LDAP). To stop these conflicts, either disable these protocols in the Exchange Server settings, or change the ports assigned to these services in either VPOP3 (in the Services page) or Exchange (using similar instructions to those above for SMTP).

1. On the Exchange Server computer go to Start → Programs → Microsoft Exchange → System Manager
2. In the System Manager, go to Recipients, then Recipient Policies on the left of the screen, then right-click Default Policy on the right, and choose Properties
3. On the E-Mail Addresses (Policy) tab, make sure that there is an entry for Type SMTP, with Address @domain.com where domain.com is the email domain which VPOP3 will forward to Exchange. Usually this is created automatically for you when you install Exchange, but it is worth checking, and adding it if it is not there.

1. In the Exchange System Manager, go to Connectors at the left of the screen.
2. Right-click Connectors and choose New → SMTP Connector
3. In the Name box enter something like Mail to VPOP3
4. Choose the Forward all mail through this connector to the following smart hosts option, and enter the IP address of the VPOP3 computer in square brackets, eg [192.168.1.1]
5. Press the Add… button and select the Exchange server name and press OK
6. Now go to the Address Space tab, and Add a new address space. Simply select SMTP and press OK twice
7. Press OK to finish creation of the outgoing mail connector

Go to the VPOP3 Local Mail tab and press the Edit LAN Forwarding button.In this window put a line like

   *@mydomain.com    192.168.1.1:5025

where mydomain.com is your registered domain, or the subdomain given to you by your ISP, and 192.168.1.1 is the IP address of the Exchange Server computer.

Also, in the In Mail tab, press Routing, and set the routing method to According to Recipienr

In the In Mail tab in the VPOP3 settings for each In Mail setting, press Routing, and set the routing method to set the Routing method to Forward to another LAN Mail Server, and in the box put something like fred@domain.com@192.168.1.1:5025

Go to the Local Mail → LAN Forwarding → Configuration page in the VPOP3 settings. In this LAN Forwarding configuration box put lines like:

  user1@mydomain.com   192.168.1.1:5025
  user2@mydomain.com   192.168.1.1:5025

You can tell VPOP3 to forward unspecified addresses to user1@mydomain.com by using:

  ~@mydomain.com     192.168.1.1:5025     user1@mydomain.com

If you want to forward ALL email addresses, use something like:

  *@mydomain.com    192.168.1.1:5025

where mydomain.com is your registered domain, or the subdomain given to you by your ISP, and 192.168.1.1 is the IP address of the Exchange Server computer.

Note that using the wildcard will forward all addresses, so should only be used if you have a VPOP3 licence which supports unlimited LAN forwarding (eg a VPOP3 Basic licence for 25 users or more, or a VPOP3 Enterprise licence).

Also, in the External Mail → In Mail page in the VPOP3 settings, make sure that the Extended Email Routing Options main radio button is set to Route According to Detected Recipient.

In the External Mail → In Mail page in the VPOP3 settings for each In Mail setting, set the Extended Email Routing Options main radio button to Forward all messages to another LAN mail server using SMTP. Then, in the configuration boxes, put the email address on the Exchange Server, and the IP address:port of the Exchange Server SMTP service.

Go to the Settings → Local Mail → LAN Forwarding → Configuration page in the VPOP3 settings.

1. Click Add Row
2. In the Address column put something like user1@mydomain.com
3. In the Server column put something like 192.168.1.1:5025

You can tell VPOP3 to forward unspecified addresses to user1@mydomain.com by using:

• Address: ~@mydomain.com
• Server: 192.168.1.1:5025
• Rewrite Address: user1@mydomain.com

If you want to forward ALL email addresses, use something like:

• Address: *@mydomain.com
• Server: 192.168.1.1:5025

where mydomain.com is your registered domain, or the subdomain given to you by your ISP, and 192.168.1.1 is the IP address of the Exchange Server computer.

Note that using the wildcard will forward all addresses, so should only be used if you have a VPOP3 licence which supports unlimited LAN forwarding (eg a VPOP3 Basic licence for 25 users or more, or a VPOP3 Enterprise licence).

Also, in the Mail Connectors → Mail Collectors → (name) page in the VPOP3 settings, make sure that the POP3 Routing option radio button is set to Route by Parsing Message Headers.

In the Mail Connectors → Mail Collectors → (name) page in the VPOP3 settings for each Mail Collector, set the POP3 Routing option radio button to Forward all messages to another LAN mail server using SMTP. Then, in the configuration boxes, put the email address on the Exchange Server, and the IP address:port of the Exchange Server SMTP service.

See also:

• Using VPOP3's Spam Filter with LAN Forwarding
• How to 'share' domains between Exchange and VPOP3

• The LAN Forwarding configuration changes in VPOP3 only affect messages which arrive after they have been applied. Messages which arrived in VPOP3 before you set the LAN Forwarding are not retrospectively forwarded on to Exchange.

• In the examples above, we use 'mydomain.com' and 'user' and '192.168.1.1'. These are examples only! Put in the appropriate details for your own configuration. Unfortunately we cannot write the exact entries that you should use in our help documents.