Is this an attack? how do i block it?

maibbu

NOQUEUE: reject: RCPT from [185.225.75.199]:55212: 550 5.7.1 Service unavailable; client [185.225.75.199] blocked using zen.spamhaus.org; from=<spameri@tiscali.it>, to=<spameri@tiscali.it>, proto=ESMTP, helo=<WIN-CLJ1B0GQ6JP>

Does this appear in the postfix logs every 30 minutes? What should I do?

esackbauer

Nothing. This address is an open relay test, and it seems spamhaus RBL is blocking it anyway.