Matt Bayliss: > [3] Output of /var/log/maillog during the session with debug_peer_list set > to client > http://pastebin.centos.org/36256/
This ends with: Nov 18 10:28:52 mailserver postfix/smtpd[31664]: < unknown[1.1.1.1]: RCPT TO:<test-2cb1eaec-bcba-4cc2-b76e-974bf87b2...@mailinator.com> ... Nov 18 10:28:52 mailserver postfix/smtpd[31664]: > unknown[1.1.1.1]: 250 2.1.5 Ok ... Nov 18 10:28:52 mailserver postfix/smtpd[31664]: smtp_get: EOF Nov 18 10:28:52 mailserver postfix/smtpd[31664]: lost connection after RCPT from unknown[1.1.1.1] Something broke the SMTP connection after Postfix replied with "250 2.1.5 Ok". I suspect that you have some spambot detection system that interferes with SMTP. > [4] TCP stream decoded acket capture of above session > http://pastebin.centos.org/36261/ This ends with: RCPT TO:<test-2cb1eaec-bcba-4cc2-b76e-974bf87b2...@mailinator.com> 250 2.1.5 Ok RCPT TO:<test-5f6f7a2d-d5f8-402e-8314-f6ef3dc46...@mailinator.com> Note that the last RCPT TO command was not delivered to Postfix. I therefore suspect that you have some anti-malware system that breaks connections when a client sends suspicious email. Wietse