Opening up another SMTP port on an Exchange 2003 Server

Once in awhile, I need to be able to access port 25 for sending SMTP (email) traffic thru an ISP that doesn't allow it. The workaround is to open a different port that is allowed (many ports over 1024 are allowed, but some like 8080 are being blocked by some ISPs). The way to do this in Exchange 2003 is non-obvious, but trivial.

When you add in a virtual SMTP server, be sure to link the SMTP connector to the virtual connection (beachhead) or mail will get stuck in the queue.

Add a virtual server for port 7777:

1. start system manager
2. open servers/your server/protocols/smtp
3. right click net/smtp virtual server
4. give it a name, click next
5. select ip address (all unassigned, probably) click finish (you'll get an error about a duplicate IP/port, but that is OK for now)
6. right click, properties on new SMTP server
7. click advanced
8. click edit
9. change TCP port from 25 to 7777, ok, ok
10. click access/authentication uncheck anonymous access!, ok
11. click relay restrictions, leave computers blank, but check "Allow all computers which
    successfully authenticate", ok

Link the virual server to the rest of the system:

1. start system manager
2. connectors/smallbusiness smtp connector
3. right click, properties
4. under local bridgeheads, click Add...
5. click on the virtual server you just selected, ok, ok

When you make a change to a virtual smtp server, you should always stop and restart it.

Now you can setup your remote email clients to use port 7777 instead of port 25. Be sure to set up the SMTP connection on the client so that the server requires authentication and uses the same credentials as the mailbox.