This window is accessed via the Security Tab on the Virtual Server Properties window. The Relay and Routing Control window gives you the ability to allow or deny IP addresses to relay messages. For security reasons, if an IP address is matched in the Allowed Relay and Denied Relay Tabs, then relay privileges will be denied. The only exception to this is if the IP address matches a network range on the Denied Access Tab, and is a Single Computer match on the Allowed Access tab.
There are three tabs available on this window, the Allowed Relay tab, the Denied Relay tab, and the Relay / Routing tab. The first two tabs both contain an Add… button that opens a separate window which is described on this page for convenience.
Allowed/Denied Relay Tab
Displays the list of computers that are allowed to connect to the Virtual Server based on the Virtual Server name on the General tab of the Virtual Server Properties window. There are four options available on this tab’s screen including Add, Edit, Delete, and Lookup IP.
When you select the Add… button, a new window titled Computer will open. This window allows you to add a single computer or group of computers to the Computers Allowed or Computers Denied field.
This optional field acts as a label for the computer you are adding to the Computers Allowed field.
Select this radio button if you are only adding a single computer Computers Allowed or Computers Denied field.
Enter the IP address of the computer you want to allow to connect to the Gateway or deny it from connecting to the Gateway.
Due to the Gateway using a computer’s IP address for allowing connections, it might be necessary to lookup an IP address based off of it domain. When you select this button, a new window will open where you can type in the domain you wish to check, and resolve it to an IP address.
Group of computers
Select this radio button if you are adding multiple computers.
Type the subnet address of the network of computers you want to add.
Type the subnet mask of the network of computers you want to add.
Selecting this radio button will add all computers to the Computers Allowed field.
If you select an existing IP Address in the Computers Allowed field, the Edit… button will become selectable. This button opens the same window as the Add… button except the fields will already contain information based on the IP Address you selected.
If you select an IP Address from the Computers Allowed or Computers Denied field, you can click the Delete button to remove it.
When you select an IP address from the Computers Allowed field or Computers Denied field, you can use the Lookup IP button to perform a reverse DNS Lookup on the IP Address. Note that this feature is only available on the Allowed Relay tab.
Relay / Routing Tab
By default, messages will be delivered to recipient mail servers using standard DNS MX record methods. Using the features available in this tab, it possible to modify the delivery to these mail servers, and the parameters used to connect to them.
This tab is useful for enabling the ability to send messages to specific recipients for an IP address that has been denied relay permissions, allowing the virtual server can operate in a locked manner. The protections applied by using these features are applied at the SMTP RCPT chitchat level before the actual message is sent. This provides a level of defense against SPAM dictionary attacks, and helps to minimize network traffic generated by SPAM messages.