Victor Duchovni put forth on 3/31/2011 12:44 PM:
> On Thu, Mar 31, 2011 at 12:20:58PM -0500, Stan Hoeppner wrote:
>
>>> No, the "google" name is just the EHLO parameter sent by the client,
>>> it is not derived from DNS lookups and not verified.
>>
>> Thanks for the clarification Viktor. I can't seem to locate any
>> documentation on the official Postfix website that defines what Postfix
>> inserts in the first received line. I'm sure I'm simply search
>> handicapped. Can you point me the relevant docs?
>
> The syntax of Received lines is specified in RFC 821/2821/5321:
>
> http://tools.ietf.org/html/rfc5321#section-4.4
No wonder I didn't find it--looking in the wrong place.
> When an SMTP server receives a message for delivery or further
> processing, it MUST insert trace ("time stamp" or "Received")
> information at the beginning of the message content, as discussed in
> Section 4.1.1.4.
>
> This line MUST be structured as follows:
>
> o The FROM clause, which MUST be supplied in an SMTP environment,
> SHOULD contain both (1) the name of the source host as presented
> in the EHLO command and (2) an address literal containing the IP
> address of the source, determined from the TCP connection.
>
> the details are at the bottom of page 58/top of 59:
>
> Time-stamp-line = "Received:" FWS Stamp <CRLF>
>
> Klensin Standards Track [Page 59]
>
> RFC 5321 SMTP October 2008
>
> Stamp = From-domain By-domain Opt-info [CFWS] ";"
> FWS date-time
> ; where "date-time" is as defined in RFC 5322 [4]
> ; but the "obs-" forms, especially two-digit
> ; years, are prohibited in SMTP and MUST NOT be used.
>
> From-domain = "FROM" FWS Extended-Domain
>
> By-domain = CFWS "BY" FWS Extended-Domain
>
> Extended-Domain = Domain /
> ( Domain FWS "(" TCP-info ")" ) /
> ( address-literal FWS "(" TCP-info ")" )
>
> TCP-info = address-literal / ( Domain FWS address-literal )
> ; Information derived by server from TCP connection
> ; not client EHLO.
So the verified reverse DNS data Postfix inserts in front of the address
literal would be the "Domain folded whitespace" mentioned above or
"address-literal FWS"? I assume the IP address in the received line
falls under "TCP-info" above.
Thanks again Viktor.
--
Stan
