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 normal.

Note that these instructions are specifically for linking VPOP3 to Exchange, they do not mention the general Exchange configuration that you will need to do. For that, see your Exchange documentation, or talk to your Exchange installer.

Note that we do not offer support for Exchange, and we are not Exchange experts, so the instructions below are following through the steps we made to configure it and have it working on a test system here. If you have slightly different requirements, then you may need to refer to the Exchange documentation.

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 Server 2007 → Exchange Management Console
2. On the left of the Management Console, choose Server Configuration, then Hub Transport. Now in the Receive Connectors section, right-click the Default-<host name> connector, and choose Properties.
3. Go to the Network tab. In the top half of this page, called Local IP Addresses select each address in turn, and press Edit… Change the Port to a different number larger than 1024, for instance 5025, and press OK.

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

1. On the Exchange Server computer go to Start → Programs → Microsoft Exchange Server 2007 → Exchange Management Console
2. On the left of the Management Console, choose Organization Configuration, then Hub Transport. On the right-hand side select the Accepted Domains tab, and make sure that your email domain is listed in there in the Accepted Domain column
3. On the E-Mail Address Policies tab, right-click the Default Policy item, and choose Edit…
4. Press Next until you are on the E-Mail Addresses section. Make sure there is an entry there under SMTP called @<yourdomain>.

Usually the above settings are set during installation of Exchange Server, but it will cause problems if they are not there, so it is worth checking.

1. In the Exchange Management Console, choose Organization Configuration, then Hub Transport. On the right-hand side select the Send Connectors tab.
2. If there is already an All Outgoing Mail connector defined, go to the next section
3. Press New Send Connector on the far right.
4. In the Name box enter something like “Mail to VPOP3”
5. In the Select the intended use box, make sure that Custom is selected. Press Next
6. On the Address Space page, press Add. In the Address box type * (asterisk) and press OK. Press Next
7. On the Network Settings page, select Route mail through the following smart hosts:
8. Press Add. Enter the name or IP address of the VPOP3 computer. Press OK. Press Next
9. On the Configure smart host authentication settings page, choose either None or Basic Authentication, as required by your VPOP3 configuration, and enter the appropriate details. Press Next
10. Press Next
11. Press New, Finish
12. Go to the Setting up VPOP3 to forwarding incoming mail to Exchange section below

If there was already an All Outgoing Mail connector defined in the Send Connectors section.

1. Right-click the All Outgoing Mail connector, and choose Properties
2. Go to the Network tab
3. Select Route mail through the following smart hosts:
4. Press Add. Enter the name or IP address of the VPOP3 computer. Press OK.
5. If your VPOP3 server requires authentication, press the Change button to set this
6. Close the All Outgoing Mail Properties window

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.

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 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

See also:

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

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 happens with 389 (LDAP). To stop these conflicts, either disable these protocols in the Exchange Server settings, or change the ports assigned to these services in the VPOP3 Services page.