[Rspamd-Users] Rspamd as milter for Postfix and 'discard' forced action

[Ralph Seichter]

I'm having trouble with Rspamd as a milter for Postfix, specifically
with Rspamd's discard action:

  # /etc/rspamd/local.d/force_actions.conf
  rules {
    FOO_RULE {
      expression = 'FOO_EXPR',
      action = 'discard'
    }
  }

  # /etc/rspamd/rspamd.local.lua
  config['regexp']['FOO_EXPR'] = {
    re = 'From=/user\\@domain\\.tld/Hi'
  }

If I use the 'reject' action in Rspamd rules like the one shown above,
Postfix rejects matching messages on arrival, as is expected. However,
the actions 'discard' and 'quarantine' have no visible effect.

Since Rspamd merely offers a suggestion on how the MTA is supposed to
treat messages, I thought I might need to configure Postfix to honor
'discard' suggestions, but I was told on the Postfix mailing list that
no extra configuration should be necessary (i.e. DISCARD is supported by
default).

Am I missing something on the Rspamd side to make this work? Postfix
calls Rspamd via "smtpd_milters=inet:localhost:11332".

-Ralph