Question
The ability to do this has been available in GMS since build 3335 at which point the settings had to be configured via the system variables. A GUI was shortly afterwards added to the last version 11 release – build 3365.
We would therefore recommend that all customers wishing to use this functionality ensure that they are running a minimum of build 3365.
Answer
Firstly, you will need to enable either or both SMTP Auth or POP/IMAP before SMTP which are authentication mechanisms available in GMS and GMS Anti-Spam respectively.
Once configured, clients should now be able to connect to your GMS server and successfully authenticate to be able to legitimately relay through your server.
If you wish to only accept SMTP connections from authenticated users, you will need to perform the following:
From the administration interface, expand the system level Anti Spam node and then "Bypasses". Now click on "AuthenticatedIP’s".
By entering at least one trusted IP address, this will effectively activate the functionality required to force authentication from every connecting client.
Therefore, any connecting client coming in from an IP not in this list must authenticate to be able to send mail through the server.
If you have a list of trusted IP’s currently in use at the “Local IP” interface from Mail > Security > Local IP, these IP’s will also need to be added to this authentication list.
See Also:
- How can I allow only one IP address to connect to my GMS server via SMTP?
- How do enable editing of Variables?
Keywords:smtp auth authentication allowed connection single one