>
>
>
> If now a user of such a domain requests that he can be blocked
> from receiving email from my domain, due to abuse of my service,
> would be a simple REJECT of his email address in the same
> transport map list be sufficient, or does postfix may get confused?
>
>
transport(5) can have "error" transport for a certain domain, there is an
example in the man page.
.example.com error:mail for *.example.com is not deliverable
But if someone abuses your service, wouldn't it be better to block the
abuser?
You can also use access(5) to block smtpd from relaying emails to some
domains
>
