How to tell if your Notes server is being used as an open relay

1. The spammers would love you.

2. If you're an open relay and your mail routing log setting is switched all the way up to 40, your log file would contain about a minute and a half of records.

3. You would, no doubt, have countless entries listing inbound SMTP connections and then transferring mail to domain whatever.com.

Not to mention that you would probably already be listed on someone's blacklist.

Seriously though, check the server's configuration document.

One method to test your server would be to use a Web service like open relay database. Be aware though, I would implement the following before testing via this service.

1. Domino Administrator
2. Configuration Tab
3. "Server" twistie
4. "Configurations" from the navigator
5. Select and open the server's configuration you want to inspect
6. "Router/Smtp" Tab in that document
7. "Restrictions and Controls" Tab
8. "SMTP Inbound Controls" Tab
9. Check options under "Inbound Relay Controls" heading
10. Check options under "Inbound Relay Enforcement" heading

What you're specifically interested in are the settings under step 9 and 10. Follow the options suggested by holding your mouse button down on the field descriptions to examine the recommended options.

Especially:

Allow messages only from the following internet hosts to be sent to external internet domains: 

and

Exclude these connecting hosts from anti-relay checks: 

To enforce relay restrictions and prevent your server being used as an open relay.

Be careful to ensure that the above mentioned settings include your own IP address ranges if any applications on your internal network utilize the Domino server for SMTP operations. Accounting packages, some other software applications and multi-function scanners/faxes are examples of things that may utilize your server as an internal SMTP "gateway."

Check your existing settings to make sure you don't restrict the operations of applications and devices from legitimately routing SMTP mail through your Domino server.