Disable greylisting based on sender address?

Hi all,

Quote from the postgrey site:
> When a request for delivery of a mail is received by
Postfix via SMTP,
> the triplet CLIENT_IP / SENDER / RECIPIENT is built

I think that including the SENDER in this triplet may lead
to rare mail
delivery failures, even when a client mailserver implements
valid
retrying (as specified by the RFC). Imagine a case where one
mailserver
sends e-mails to an account on the other server about every
fourty,
every time with a different sender address. Since most
servers keep
track of the states of other mailservers (down/up), this can
happen in
rare cases:

00:00:00 sending mail from firstaa.net to bobfoo.net:
temporary
failure (greylisted by foo.net MX)
00:00:40 sending mail from secndaa.net to bobfoo.net:
temporary
failure (greylisted by foo.net MX)
00:01:00 retrying firstaa.net -> bobfoo.net: not retrying,
since MX of
foo.net has state "failure"
00:01:20 sending mail from thirdaa.net to bobfoo.net:
temporary
failure (greylisted by foo.net MX)
00:01:40 retrying secndaa.net -> bobfoo.net: not retrying,
since MX of
foo.net has state "failure"
00:02:00 retrying firstaa.net -> bobfoo.net: not retrying,
since MX of
soo.net has state "failure"
00:02:00 sending mail from fourthaa.net to bobfoo.net:
temporary
failure (greylisted by foo.net MX)
00:02:40 retrying secndaa.net -> bobfoo.net: not retrying,
since MX of
foo.net has state "failure"
00:02:40 sending mail from fifthaa.net to bogfoo.net:
temporary
failure (greylisted by foo.net MX)
00:03:00 retrying firstaa.net -> bobfoo.net: not retrying,
since MX of
foo.net has state "failure"
00:03:00 retrying fourthaa.net -> bobfoo.net:
not retrying, since MX
of foo.net has state "failure"

etcetera.


To avoid this rare type of delivery failures, it is probably
a better
idea not to use the "sender" component of the
triple. I don't see any
disadvantages of dropping that component: I never saw a
spammer sending
multiple spam messages to the same recipient, but with a
different
sender addresses.

I hope you know what I mean, because it's kind of hard to
explain my
point...

Regards,

  -- Bas van Schaik

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