Trying to block a whole domain, syntax seems right, but email is delivered anyway:smtpd.conf:match mail-from "@domain.com" for any reject Did I miss something?
Without a "from something", "from local" is assumed. So your match doesn't apply for remote senders. Add "from any":
match from any mail-from "@domain.com" for any reject (And it has to be above accept actions since first match wins.)
