Re: repeated attempts delivering mail to 'unknown user@samedomain'
lars brun nielsen schrieb:
> Feb 6 08:11:27 celery postfix/smtpd: reject: RCPT from shawidc-mo1.cg.shawcable.net[18.104.22.168]: 550 <MULRVNHSVJM@DOMAIN.XX>: User unknown; from=<> to=<MULRVNHSVJM@DOMAIN.XX>
"<>", an empty Return-Path:/Envelope-Sender, so those are bounces /
> an explanation eludes me, [...]
Somebody is spamming while using adresses from your domain as the
faked sender of those spam-mails. That's quite old news for some
years; SPF was invented to avoid that. If you're lucky, you'll get
some hundred of those bounces and be done with; if your're unlucky,
you'll get some hundred *thousand* of them, or even more.