This 419 slipped past all our defences. None of the usual "nigerian" rules
in SpamAssassin fired.
However, it appears that had we presented an ESMTP SIZE parameter with the
callback, we could have known something was up:
220 mk-cpfrontend.uk.tiscali.com ESMTP Service (6.7.018) ready
EHLO bowling.cent.gla.ac.uk
250-mk-cpfrontend.uk.tiscali.com
250-DSN
250-8BITMIME
250-PIPELINING
250-HELP
250-AUTH CRAM-MD5 DIGEST-MD5 PLAIN
250-DELIVERBY 300
250 SIZE
MAIL FROM: <> SIZE=1000
250 MAIL FROM:<> OK
RCPT TO: <bekimulete@???>
552 RCPT TO:<bekimulete@???> Mailbox disk quota exceeded
No doubt the mailbox was full due the overwhelming number of replies from
people eager to take up the kind business proposal ;-)
As I understand it, part of the rationale of callbacks is to check a
sender address is valid, so if we have to send back a bounce for some
reason, we can do so OK. If instead it appears impossible to send a
bounce, then policy allows us to refuse to accept the mail in the first
place.
So it doesn't seem too much of a stretch to attempt to check we can send a
bounce of a plausible SIZE ?
Just a thought!
Chris
--
Chris Edwards, Glasgow University Computing Service
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Date: Sun, 5 Oct 2003 21:34:07 GMT
From: bekimulete@???
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Subject: From:Beki
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>From ;Beki
Good Day,
With warm hearts I offer my friendship, and my greetings, and I hope this
letter meets you in good time. It will be surprising to you to receive
this proposal from me since you do not know me personally. However, I am
sincerely seeking your confidence in this transaction, which I propose
with my free mind and as a person of integrity.
[ snip ]