spf-discuss
[Top] [All Lists]

Re: Maybe simple question

2003-12-12 21:25:48
On Friday 12 December 2003 04:29 pm, Ned Harvey wrote:
Ok, so I understood it correctly from the start then.  Under SPF, the 
receiver's mailserver has to know the IP address that the message came from.  
But it doesn't.  It only knows the last relay that hands the message over.

Email is almost never a direct operation, Wechsler.  Look at your own 
messages.  The ones you send to this list go through 5 relays before 
arriving.

Even though I'm new to this list, I think I know why your confused.


Two points above.


The terminology is ambiguous and needs to be clarified.

http://www.infinitepenguins.net/SPF/index.php

is part of the problem.

They say (third entry)

Mail Sender (from: email addy)    (eg wechsler(_at_)infinitepenguins(_dot_)net) 

Which makes you think they are talking about the From:  in your mailer (MUA).

I suggest they change this to :-

MAIL FROM: (return path - MTA)   -  May or may NOT be the same as the FROM: in 
your MUA

which should help to clarify things.

Second point.  You must remember that each connection is a direct SMTP link.  
They are separate.  Each MTA add's some additional information, date/time, 
server receiving the mail and IP of the remote mail etc.
If that's it's final destination,. it is done.  If not it starts a new SMTP 
connection to another server.
This can depend on whether :-

They have multiple mail servers that pass it along (large systems).
A mailing list.
A mail forwarder.

The point to remember, is, that the MTA (mail server) that is processing the 
message, will change the return path to it's name, when it connects to the 
next MTA, it will say :-

MAIL FROM:  <with it's return path name>  NOT your original MUA (email 
address)  name.

It's late and I'm tired.  If it's still unclear, I will try again once i get 
some weekend choirs completed.

Regards...Martin
-- 
Hard work never killed anybody, but why take a chance?
                -- Charlie McCarthy

-------
Sender Permitted From: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
Latest draft at http://spf.pobox.com/draft-mengwong-spf-02.9.3.txt
To unsubscribe, change your address, or temporarily deactivate your 
subscription, 
please go to 
http://v2.listbox.com/member/?listname(_at_)©#«Mo\¯HÝÜîU;±¤Ö¤Íµø?¡