In the application web interface window, select the Settings → Built-in MTA → Basic Settings section.
In the Domain name text box, type the domain name of Kaspersky Secure Mail Gateway (mydomain) that all cluster nodes will share.
Select the name that cluster nodes will use as the host name (myhostname):
If you want each node to use its own fully qualified domain name that was assigned to it during deployment, select Use FQDN of cluster nodes.
If you want all cluster nodes to use a common name, select Use specified hostname, and in the text box, enter the fully qualified domain name of the Kaspersky Secure Mail Gateway.
In the Message size limit (bytes) field, specify the maximum size of an email message including SMTP headers that can be forwarded through Kaspersky Secure Mail Gateway (message_size_limit), in bytes.
Specify 0 if no limit is required.
The default value is 20971520 bytes (20 MB).
Create a list of trusted networks and network hosts that are allowed to send email messages via Kaspersky Secure Mail Gateway (mynetworks). To do so, enter the host IP addresses and/or network addresses in CIDR format in the Trusted networks field and press ENTER.
As a rule, these are internal networks and network hosts of your organization. For example, you can specify the IP addresses of Microsoft Exchange servers used at your organization.
You can type addresses one by one or paste a whole list of semicolon-separated networks.
If trusted networks are not specified, Kaspersky Secure Mail Gateway will not be receiving messages from internal mail servers and redirect them outside the network of your organization.
Under Email destination address, select how Kaspersky Secure Mail Gateway will forward email messages:
If you want to use your DNS server settings for email routing, select Send directly.
If you want to send messages through an edge gateway, select Send through an edge gateway.
If at the previous step you selected the edge gateway option:
Enter the address and port of your edge gateway (relayhost). Kaspersky Secure Mail Gateway will be redirecting all messages to this address.
You can enter an IPv4 address (for example: 192.168.0.1), an IPv6 address (for example: 2607:f0d0:1002:51::4), domain name or FQDN.
If you have configured email routing for individual domains, Kaspersky Secure Mail Gateway will be redirecting email messages to the addresses specified for each domain.
If you specified a domain name, you can enable MX record lookup for it. To do so, select the Use MX lookup check box.