Re: [Exim] Howto hide the server domain in the HELO dialog?

Top Page
Delete this message
Reply to this message
Author: The still most prejudiciously configured Exim User's Mailing List
Date:  
To: Danny Bendersky
CC: Edgar Lovecraft, Exim User's Mailing List
Subject: Re: [Exim] Howto hide the server domain in the HELO dialog?
[ On Monday, March 8, 2004 at 12:41:48 (-0300), Danny Bendersky wrote: ]
> Subject: Re: [Exim] Howto hide the server domain in the HELO dialog?
>
> Hi, I need to do this because one customer that serve lot of domains
> want to see his domains at the helo level and not my domains.


You _MUST_NOT_ hide the server hostname in the greeting dialog.

The server _MUST_ include its proper canonical hostname (i.e. a name
that resolves to the IP address it listens on) in the 220 message.

The client _MUST_ send its canonical hostname (i.e. a name that resolves
to the IP address its connection is originating from) in the HELO or
EHLO command.

These are absolute "MUST" requirements in the standard SMTP protocol
and host-requirements definitions. RTFRFCs

If your customer's clients want their own domains in the SMTP envelope
then they're free to run their very own mailers on their very own static
IP addresses with their very own policies and procedures.

There is absolutely no advantage to pretending anyone can hide any
information about who really runs the mail server for a given domain in
any case. Anyone with two neurons to rub together can figure it out
from the DNS and IP addresses involved anyway and anyone thinking they
can hide such public information obviously doesn't have enough neurons.

--
                        Greg A. Woods


+1 416 218-0098                  VE3TCP            RoboHack <woods@???>
Planix, Inc. <woods@???>          Secrets of the Weird <woods@???>