Artem Bokhan a écrit : > Ok, let's start with beginning... > > What is the difference between NAME and REVERSE_NAME from postfix's view? > What is the difference between "SMTP client hostname" and "PTR record > value"? >
NAME is "verified". REVERSE_NAME is not. so you have 3 cases: - NAME=REVERSE_NAME != "unknown". this is when everything is correctly configured and there are no DNS problems - NAME=REVERSE_NAME = "unknown". for example, if the IP doesn't resolve to a PTR. - NAME="unknown", REVERSE_NAME != "unknown". This is when the has a PTR, but it can't be verified (it doesn't resolve back to the IP), either because of a misconfugration or because of a DNS problem. here is an example: $ host -t PTR 147.203.208.166 166.208.203.147.in-addr.arpa domain name pointer redirector-vm01-evip-aol.cherryimprovise.com. $ host -t A redirector-vm01-evip-aol.cherryimprovise.com redirector-vm01-evip-aol.cherryimprovise.com has address 147.203.208.196 as you can see, the last IP doesn't match the original one, so the hostname is "unknown" but the PTR is "redirector......com". In this case, postfix would log: Jan 29 00:38:16 imlil postmx/smtpd[26222]: warning: 147.203.208.166: address not listed for hostname redirector-vm01-evip-aol.cherryimprovise.com => postfix tells you that the PTR is unverified. Jan 29 00:38:16 imlil postmx/smtpd[26222]: connect from unknown[147.203.208.166] => postfix sets the hostname to "unknown" Jan 29 00:38:17 imlil postmx/smtpd[26222]: NOQUEUE: reject: RCPT from unknown[147.203.208.166]: 550 5.7.1 Client host rejected: cannot find your hostname, [147.203.208.166]; from=<3ff.4.69709687-17084...@cherryimprovise.com> to=<mo...@netoyen.net> proto=ESMTP helo=<redirector-vm01-evip-aol.CherryImprovise.com> => as you can see, reject_unknown_client rejects this even if it has a PTR. Before you ask, reject_unknown_client is triggered by the sender address format, which I've only seen in snowshoe spam.
