robert fitzpatrick wluhewebtentnet tue 20080226 1123 0100 ralf hildebrandt wrote robert fitzpatrick last almost 24 hours postfix complaining running processes feb 25 145236 esmtp postfixmaster97965 warning service smtp 25 reached process limit 100 new clients may experience noticeable delays youre attack yes finally found attack address one particular domain domain received 60k log entries since midnight known highest volume domain less 1000 course messages coming different ips rejected user unknown via verification process postfix instance feb 26 054618 esmtp postfixsmtpd96399 noqueue reject rcpt bbnmainserverbluebonnetnutritioncom20791172154 450 411 recipient address rejected undeliverable address host xxxxxxxx said 553 530 user reply rcpt command protoesmtp helo fight attacks like thanks robert thu 07 aug 2008 204533 0500 number rejections exploded