kumomta/docs/reference/kumo/make_egress_source/socks5_proxy_server.md

socks5_proxy_server

{{since('2023.06.22-51b72a83')}}

Optional string.

If both socks5_proxy_server and socks5_proxy_source_address are specified, then SMTP connections will be made via a SOCKS5 Proxy server.

socks5_proxy_server specifies the address and port of the proxy server.

{{since('2026.09.22-a276d4a8')}} Can be a DNS host name + port (proxy.example.com:5000) in addition to an IP literal (10.0.0.1:5000, [::1]:5000). DNS names are resolved at connection time; if resolution returns multiple addresses, each is tried in turn until one connects successfully or the configured connect_timeout elapses. In earlier versions, only IP literals were supported.

kumo.on('get_egress_source', function(source_name)
  if source_name == 'ip-1' then
    -- Make a source that will emit from 10.0.0.1, via a proxy server
    kumo.make_egress_source {
      name = 'ip-1',
      socks5_proxy_source_address = '10.0.0.1',
      socks5_proxy_server = '10.0.0.1:5000',
      ehlo_domain = 'mta1.examplecorp.com',
    }
  end
  error 'you need to do something for other source names'
end)