Mail Relay Parameters

The Mail Relay Parameters, together with the SMTP Connection Policies, are important parameters for the security of your ZixGateway appliances. They regulate who is allowed to route mail through the server and where messages about system events are sent.

Mail Relay Parameters are:

• Networks Served by Mail Relay
• Outgoing Mail Relay
• System Notification Address

Networks Served by Mail Relay

Optional, Defaulted

The Networks Served by Mail Relay parameter enumerates the physical IP subnets that are served by the ZixGateway appliance. This partial map of your network is not directly interpreted by the mail relay. Instead, it is used by the SMTP Connection Policies as a constituent parameter for one of its policies.

The Networks Served by Mail Relay parameter is server-defaulted to match just the subnets on which the ZixGateway appliance host resides.  

ZixCorp recommends that you provide a value that overrides this default with any of the IP subnets to which you would like to grant relay privileges.

The legal values of this parameter are a list of IP address masks separated by commas. An IP address mask is a string of the form <IP_address>/<#_of_bits_in_mask>.

Examples:

• 192.168.0.0/16 is a class-B subnet mask, with the lower order 16 bits masked (wildcarded) to match any subnet and node with the prefix 192.168.
• 192.168.15.0/24 is a class-C subnet mask that matches any node on the 192.168.15 subnet.
• 192.168.15.XX/32 matches a specific node on the 192.168.15 subnet.

Outgoing Mail Relay

Optional, Defaulted

Under normal circumstances, a ZixGateway appliance routes the message directly to its final destination when it finishes processing a message. In some cases, however, you might want this routing and relaying function to be performed by another mail relay and not by the ZixGateway appliance.

• The server-default for this parameter is to have ZixGateway route all mail to its final destination and not to have a downstream mail relay.

ZixCorp recommends that you accept this default.

• To have ZixGateway forward all messages to another mail relay, type the domain name, hostname, or IP address of the other mail relay in the Outgoing mail relay field.
• If multiple mail relays are required, type a hostname or domain name that resolves to multiple IP addresses.

Note: If you have TLS configured in your policies, email will no go through any Outgoing Mail Relay you have set up.

System Notification Address

Required, User-defined

This parameter allows you to automatically redirect email to specified administrator email addresses. Some automatically generated emails, such as those announcing system events, need to be routed to a real administrator.

To route messages to an actual administrator responsible for the health and operation of your ZixGateway appliance host machines, enter the email address in the System Notification Address field.

If you would like these messages to go to more than one email address, enter each address, separated by commas.

Main Topic

Configure Appliance: System