Author: Edgar Lovecraft Date: To: exim-users, Greg A. Woods Subject: Re: [Exim] Howto hide the server domain in the HELO dialog?
Greg A. Woods wrote: >
>[ 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
> Yes Greg you are correct, and if you check my original reply to this you
will see that I specifically told him that he would need to set the
HELO name during any smtp transaction when he sends email.
We all do know that you must have a HELO hostname :) >
> 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.
> They could do that, or there is also the option of virtual IP's on the
servers that Danny runs, or just use multiple servers (point also already
made by me previously). >
> 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.
> That may or may not be the case in this instance to where the client
would 'like to hide' who really runs the servers, and if it is all setup
'correctly??' there really is not much of a way to determine who runs a
particular server when multiple IP addresses/and or multiple servers are
involved (at least it would make it more difficult).
However, I do agree that when you hire one company to host and or relay
your email for you, then it should be a given that it is going to be the
hosting/relaying companies information that gets passed along in any SMTP
transaction, if for no other reason, just so everyone knows WHO to contact
when there are delivery problems, thus why the company I work for never
considers such a setup, either use our serives or don't, but it would not
be impossible to make such considerations, just more overhead in the
administration (we choose less overhead).
Cheers!
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