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Configuring SMTP Listeners

An SMTP listener can be defined using the kumo.start_esmtp_listener function.

The kumo.start_esmtp_listener function can be called multiple times to define multiple listeners. Each listener can have its own relay list, banner, hostname and list of controls to determine domain behavior.

In the example below you can see the definition of IP address, Port, and specific relay hosts that are permitted to use that listener.

kumo.start_esmtp_listener {
  listen = '',
  hostname = '',
  relay_hosts = { '', '' },

Refer to the start_esmtp_listener chapter of the Reference Manual for detailed options.

For most use cases, it will be necessary to configure listeners on a per-domain basis regarding inbound traffic. This includes designating which domains are allowed for inbound relay and bounce/feedback loop processing. See the Configuring Inbound and Relay Domains section of the User Guide for more information.

Last update: 2023-06-12
Created: 2023-03-13