We will create a new multimap to selectively block specific senders using the mail envelope. Our rule will filter based on the right hand side only – matching the domain part of the envelope email:domain. In addition we will use the prefilter attribute with action = "reject"; to avoid subsequent costly tests – reject will be the treated as ultimate decision for this mail.

Alternatively we can also filter on the full e-mail address email:addr.

/etc/rspamd/local.d/multimap.conf

sender_envfrom_deny {
  description = "Sender envelope from deny list";
  type = "from";
  filter = "email:domain";
  map = "$LOCAL_CONFDIR/local.d/maps.d/sender_envfrom_deny.map.local";
  symbol = "SENDER_ENVFROM_DENY";
  prefilter = true;
  action = "reject";
}

/etc/rspamd/local.d/maps.d/sender_envfrom_deny.map.local

example-domain1.com
info.example-domain2.com