Now with that interpretation of the log, this makes sense. I was thinking rate and concurrency were different things.
Original Message From: wie...@porcupine.org Sent: January 11, 2019 4:21 AM To: postfix-users@postfix.org Reply-to: postfix-users@postfix.org Subject: Re: concurrency rate limit li...@lazygranch.com: > I'm wondering if I have my rate limiting set up correctly. Note I have > that perl script that sniffs out dynamic IP addresses, so I am not sure > how this user is even getting concurrent connections. Postfix receives more than 4 concurrent connections at a rate of more than 10 connections over some time interval, and closes excess connections. If you want to prevent that such connections reach Postfix, then you need to do that *outside* Postfix, during the TCP handshake. Postfix does not implement TCP. That happens in the kernel. Wietse
