This plugin delivers to another mail server. This is a common setup when you want to have a mail server with a solid pedigree of outbound delivery to other hosts, and inbound delivery to users.

In comparison to queue/smtp_forward, this plugin makes a connection at MAIL FROM time to the ongoing SMTP server. This can be a benefit in that you get any SMTP-time filtering that the ongoing server provides, in particular one important facility to some setups is recipient filtering. However be aware that other than connect and HELO-time filtering, you will have as many connections to your ongoing SMTP server as you have to Haraka.


  • smtp_proxy.ini

    Configuration is stored in this file in the following keys:

    • enable_outbound=[true]

    SMTP proxy outbound messages (set to false to enable Haraka's separate Outbound mail routing (MX based delivery)).

    • host=HOST

      The host to connect to.

    • port=PORT

      The port to connect to.

    • connect_timeout=SECONDS

      The maximum amount of time to wait when creating a new connection to the host. Default if unspecified is 30 seconds.

    • timeout=SECONDS

      The amount of seconds to let a backend connection live idle in the proxy pool. This should always be less than the global plugin timeout, which should in turn be less than the connection timeout.

    • max_connections=NUMBER

      Maximum number of connections to create at any given time.

    • enable_tls=[true|yes|1]

      Enable TLS with the forward host (if supported). TLS uses options from the tls plugin.

    • auth_type=[plain|login]

      Enable PLAIN or LOGIN SMTP AUTH. This is required to enable AUTH.

    • auth_user=USERNAME

      SMTP AUTH username to use.

    • auth_pass=PASSWORD

      SMTP AUTH password to use.