By default, Kaspersky Secure Mail Gateway uses the settings of your DNS server for email routing. To configure email routing manually, create a transport map: enter the names of the domains for which email messages are intended and then type the IP addresses or FQDN names of the domains to which Kaspersky Secure Mail Gateway will be redirecting messages intended for the domains.
For example, if you want messages intended for the example.com domain to be redirected to the address 1.1.1.0:25, add the example.com domain to the transport map and then specify the IP address 1.1.1.0 and port number 25 for routing messages intended for the example.com domain.
To configure email routing for a domain:
You can enter an IPv4 address (for example: 192.0.0.1 or 192.0.0.0/16), an IPv6 address (for example: 2607:f0d0:1002:51::4), or subnet address in CIDR format (for example: fc00::/7).
Email routing is configured for the domain.