Stan Hoeppner: > Would someone kindly point me to the docs that describe the behavior of > smtpd socket open time in relation to clients that do connection caching?
http://www.postfix.org/postconf.5.html#smtpd_timeout It's stress-dependent. > I've been assisting in a troubleshooting effort. A sendmail/mailman > based list server is opening more than 4 concurrent connections to my MX > even when it has less than a half dozen messages to deliver, which > suggests connection caching on their end is not working properly. Does your box have multiple IP addresses? When Sendmail gets a 4XX RCPT TO reply, it will try to connect to an alternate address WHILE KEEPING THE 4XX-ed CONNECTION OPEN. I see this all the time with my postscreen setup. postscreen listens on multiple IP addresses, and uses postscreen_whitelist_interfaces to block clients that connect to the backup address only. Wietse
