spf-discuss
[Top] [All Lists]

Re: SRS requirements

2004-01-14 12:42:11
Quoting wayne (wayne(_at_)midwestcs(_dot_)com):
In <20040114183412(_dot_)GA6875(_at_)dumbo(_dot_)pobox(_dot_)com> Meng Weng 
Wong <mengwong(_at_)dumbo(_dot_)pobox(_dot_)com> writes:

Plan C: database


The big problem with any sort of database scheme is trying to
coordinate all MTAs about the status of the rewritten headers.

Some MTAs will do "sender callbacks", so if the forwarder site sends
email to the receiver site, the receiver will try connecting to the
fowarder to see if the envelope will be accepted or not.  (Let's skip
the discussion about whether sender callbacks are a good idea or not,
it is done often enough that it must be considered.)  This means that
that all incoming MTAs must instantly know about the envelope-froms
that are generated by all outgoing MTAs.

I don't think this is a problem, at least not the way I am thinking
about implementing SRS.  The MX handler for the rewritten sender
will accept anything addressed to the bounce handler domain, look
for the magic parts, and generate a bounce if appropriate.  A
callback will get a 250 for the RCPT and should be happy.

John Capo


If the database system is *only* used in the rare cases that a
rewritten envelope-from exceeds some limit, then it can be shuffled
off to a specific machine to deal with.

So, most of the time, the envelope-from would look like
bounce+foo#aol(_dot_)com-J0*dG7h8yzAwB=bar#pobox(_dot_)com(_at_)bounce(_dot_)pobox(_dot_)com

But in the case of
very(_dot_)long(_dot_)local(_dot_)part(_dot_)that(_dot_)is(_dot_)already(_dot_)close(_dot_)to(_dot_)the(_dot_)limit(_at_)aol(_dot_)com,
 the
email processing on pobox.com could be done by a seperate machine and
the rewritten envelope-from would look like:

21asd39kw8x02(_dot_)dk8w09llwr(_at_)database01(_dot_)bounce(_dot_)pobox(_dot_)com

The local part would be a key to the database that *only* needs to be
found on the specific machine database01.bounce.pobox.com.



-wayne

-------
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-02.9.4.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?¡

-------
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-02.9.4.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?¡


<Prev in Thread] Current Thread [Next in Thread>