>Cc: exim-users@???
>From: Tor Slettnes <tor@???>
>Subject: Re: [Exim] Matching bounce recipients against sender hashes
>To: Christian Balzer <chibi@???>
>Date: Fri, 11 Jun 2004 09:36:45 -0700
...
>I think I will send an e-mail to Evan Harris, suggesting that he:
> - at some point in the future, consider writing up an RFC on
>greylisting;
> - in that RFC, include a convention on including a unque ID in the
>envelope
> sender, such as "<local_part>+<unique_id>@<domain>".
You need to be careful here, as email addresses of the above form
are used by some email systems. The MMDF mail system uses the "="
character instead of the "+" character for its own purposes. From
the manual page for maildelivery:
MMDF treats local addresses which contain an equals sign
('=') in a special manner. Everything in a local address
from an equals sign to the '@' is ignored and passed on to
the local channel. The local channel will make the entire
string available for matching against the addr string of the
.maildelivery file. For example, if you were to subscribe
to a digest as "foo=digest@???", submit and the local
channel will verify that it is legal to deliver to "foo",
but then the entire string "foo=digest" will be available
for string matching against the .maildelivery file for the
addr field.
I believe sendmail uses the "+" character for much the same purpose.
Problems may arise if exim is being used as a relay. You won't
necessarily know what systems you are delivering mail to, or
receiving mail from. There may be a good risk of confusion if
different systems are using the same operator (+) for totally
different purposes.
