In the old check_rcpt ruleset we used
R$* % $* $: relay attempt R$* @ $* < @ $* . > $: relay attemptto detect unauthorized relaying by using addresses like these:
firstname.lastname@example.org @relay.com:email@example.comHowever, addresses like
firstname.lastname@example.org @relay.com:email@example.com probably valid in your domain (if it is
relay.com). So, what can we do about this? First: we can ignore it: they should use correct e-mail addresses, not this stuff. Second, we could try to handle it too. This requires in principle to do the same stuff as it is done in ruleset 0. If ruleset 0 resolves the address to the
localmailer, the address is ok. However, it is worth it?
There is a new proposal which tries to overcome these deficiencies.