J Doe: > Hello, > > I noticed something interesting in my logs today. I am running Postfix 3.3.1: > > Aug 24 21:09:25 server postfix/submission/smtpd[10256]: connect from > unknown[unknown]:unknown > Aug 24 21:09:25 server postfix/submission/smtpd[10256]: lost connection > after CONNECT from unknown[unknown]:unknown > Aug 24 21:09:25 server postfix/submission/smtpd[10256]: disconnect from > unknown[unknown]:unknown commands=0/0 > > It is clear that this was a bad connection, but under what > circumstances does Postfix consider a remote connection?s address > as ?unknown? ? Wouldn?t Postfix always know the remote IPv4/IPv6 > address because when a client connects to the server the address > is passed from the OS to Postfix ?
"unknown" clients are defined in http://www.postfix.org/postconf.5.html#reject_unknown_client_hostname reject_unknown_client_hostname (with Postfix < 2.3: reject_unknown_client) Reject the request when 1) the client IP address->name mapping fails, or 2) the name->address mapping fails, or 3) the name->address mapping does not match the client IP address. Wietse
