via

Since: Dev Builds Only

The functionality described in this section requires a dev build of KumoMTA. You can obtain a dev build by following the instructions in the Installation section.

Define listener-ip-specific parameters. The value is a cidr-map that is keyed by the local IP address and whose values are esmtp listener parameters.

Note

This option only really makes sense when used together with a wildcard listen value of 0.0.0.0 for an IPv4 listener or :: for an IPv6 listener.

This option can be useful to implement IP-based virtual hosting on multi-homed systems where many IP addresses are served from the same service on the same port.

kumo.start_esmtp_listener {
  listen = '0.0.0.0:25',

  via = {
    -- When clients connect to this server via its 10.0.0.1 IP
    -- address, we will use the hostname and TLS parameters
    -- defined in this block
    ['10.0.0.1'] = {
      hostname = 'mx.example-customer.com',
      tls_certificate = '/path/to/customer1.cert',
      tls_private_key = '/path/to/customer1.key',
    },
    -- When clients connect to this server via its 10.0.0.2 IP
    -- address, we will use the hostname and TLS parameters
    -- defined in this block
    ['10.0.0.2'] = {
      hostname = 'mx.other-customer.com',
      tls_certificate = '/path/to/customer2.cert',
      tls_private_key = '/path/to/customer2.key',
    },
  },
}