From 71fb4a4f845a6d4a58f010e5d3146ab8406ead78 Mon Sep 17 00:00:00 2001 From: prim-8 Date: Mon, 4 May 2026 14:33:36 -0700 Subject: [PATCH] =?UTF-8?q?postfix:=20raise=20smtpd=5Fclient=5Fconnection?= =?UTF-8?q?=5Frate=5Flimit=2010=20=E2=86=92=20100?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- postfix/postfix-main.cf.template | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/postfix/postfix-main.cf.template b/postfix/postfix-main.cf.template index c8e44b7..6a90044 100644 --- a/postfix/postfix-main.cf.template +++ b/postfix/postfix-main.cf.template @@ -31,7 +31,11 @@ command_time_limit = 30s maillog_file = /var/log/postfix.log # Rate limiting - prevent abuse/DoS -smtpd_client_connection_rate_limit = 10 +# Connection rate limit is per source IP per anvil_rate_time_unit. +# 10 was too low for load testing (20 concurrent users from one IP exhausted +# the limit in ~10s, causing connection resets for users 11-20). 100 allows +# realistic concurrency headroom while still protecting against DoS. +smtpd_client_connection_rate_limit = 100 smtpd_client_message_rate_limit = 50 smtpd_client_recipient_rate_limit = 100 anvil_rate_time_unit = 60s