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Re: spam blocking experiences with MXs
- To: misc_(_at_)_openbsd_(_dot_)_org
- Subject: Re: spam blocking experiences with MXs
- From: Robert Waldner <waldner_(_at_)_waldner_(_dot_)_priv_(_dot_)_at>
- Date: Sat, 21 Dec 2002 18:57:02 +0100
On Sat, 21 Dec 2002 09:13:58 EST, "Joseph C. Bender" writes:
>>So, delivering the spam instantly would cost you about 7.300 bytes,
>> retries every 30 minutes for 5 days amounts to 45 kB or roughly 6
>> times as many bytes.
> Your math is slightly off.
>The MX-bouncer daemon doesn't even get that far. It does a 450 after the
>redirect happens in pf. So you'd just be doing the smtp protocol overhead
>up to that point.
Not right away, it first acknowledges "helo", "mail from", and "rcpt to".
The 450 is sent after receiving "data".
If I talk to the bouncer on localhost like:
waldner_(_at_)_fsck->~ $ telnet localhost 8025
Connected to localhost.
Escape character is '^]'.
220 fsck ESMTP spamd IP-based SPAM blocker; Sat Dec 21 18:52:57 2002
250 Hello, please to meet you
250 You are about to try to deliver spam.
250 And we will try to punish you for it.
450 SPAM. http://www.spews.org?x=127.0.0.1
Connection closed by foreign host.
and count the bytes with tcpdump, 1470 comes out.
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