Seems I’ve been on the end of a fair amount of backscatter because some clueless nimrod of a spammer used enlartenment.com as the SMTP sender domain of one of their mailouts.
I found the attempt mildly amusing. It basically provided a free benchmark for my MySQL server 
Despite having only a 512 ADSL line and commodity hardware running the server, I barely noticed a thing - not one message hit the queue and the bandwidth overhead was negligible.
For the visual person, here’s today’s reject graph from mailgraphÂÂ
Y’see, when idiots use a nonexistent address to spam some other idiots who’ve set their SMTP servers to reject rather than discard obvious spam, you get null-sender bouncebacks to the unfortunate sucker in the Return-Path.
However, greylisting really makes the last part of the equation lots of fun - Idiots 2-7000 (sending the backscatter) not only have to deal with the double-bounces generated by a DSN sent to a nonexistent address, but the temp failures due to me telling your service to piss off and come back later (the aforementioned greylisting).
Perhaps this will teach admins to discard/quarantine spam rather than just reject it. Especially those sucker^H^H^souls running Sendmail.
Tags: networking
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