Shawn Heisey: > smtpd_delay_reject = yes This will apply the client, helo, and sender restrictions AFTER Postfix receives the RCPT TO command.
In other words, Postfix never applies restrictions when the client connects, when the client send EHLO, or when the client sends the MAIL FROM command. > May 18 16:19:29 nexus2 postfix/smtpd[18002]: connect from > monitor.example.com[10.2.1.39] > May 18 16:19:29 nexus2 postfix/smtpd[18002]: improper command pipelining > after MAIL from monitor.example.com[10.2.1.39] This applies restrictions before RCPT TO, so you reported the wrong Postfix configuration, or you have parameter settings in master.cf that you should also report about. Wietse