message:add_authentication_results(server_id, results)

Since: Version 2023.11.28-b5252a41

The functionality described in this section requires version 2023.11.28-b5252a41 of KumoMTA, or a more recent version.

This method will prepend an Authentication-Results header to the message, as specified by RFC 8601.

The parameters are:

• server_id - the authserv-id. It is suggested to use msg:get_meta('hostname') to obtain the hostname that was configured in the corresponding SMTP listener.
• results - an array of authenticationresult objects holding the results of various authentication methods.

Example: obtaining DKIM authentication results

kumo.on('smtp_server_message_received', function(msg, conn_meta)
  -- Verify the dkim signature and return the results.
  -- Note that this example isn't making any policy decisions;
  -- it is only annotating the message with the results and
  -- allowing it to be relayed
  local auth_results = msg:dkim_verify()

  local spf_result = kumo.spf.check_host(
    msg:sender().domain,
    conn_meta,
    tostring(msg:sender())
  )

  -- add the spf authentication result to our collection of results
  table.insert(auth_results, spf_result.result)

  -- Add the results to the message
  msg:add_authentication_results(msg:get_meta 'hostname', auth_results)
end)

might produce an Authentication-Results header like this:

Authentication-Results: hostname.example.com;
        dkim=pass
        header.a=rsa-sha256
        header.b=jo0EO4dX
        header.d=github.com
        header.i=@github.com
        header.s=pf2023
        spf=pass

See Also:

• msg:dkim_verify()