I would like to be able to configure GMS to only accept SMTP connections from clients/servers that must first authenticate to the server. How can this be achieved?
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.
If you are running a version that is prior to the release of build 3075, this functionaity can still be achieved but it will have to be done through “Domain Variables”.
Simply edit the domain variables and add a new variable with a name of "BypassAuthIP" and a value of the IP address range you wish to allow through. If you wish to allow through more than a single IP address or range of IP addresses, use a space separated list or a wildcard.
Keywords:anti spam JUCE antispam bypass IP smtp authentication force accept