the corner office

a blog, by Colin Pretorius

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I've never used Mailinator but (via there's an interesting article about its architecture: a completely transient mail server which stores a heap of emails in memory, and then forgets about them. Great for sign-up emails and the like. Oh, and implemented in Java, and running on a 2GHz server with a gig of memory, which makes it extra-interesting.

One thing the Mailinator system does, which caught my eye, was that the server takes very long to reply to incoming mail, when it can afford to. The reason is quite simple: slow responses will choke up spammers who're trying to spew out as many emails as quickly as possible. This is something I've wondered about before: have lots and lots of honeypot addresses, and dummy mail servers which take forever to reply. For your average server out there, which has a fair amount of spare capacity, why not dedicate a handful of threads to ruining a spammer's day?

{2007.04.01 - 01:52}


1 hugo (2007.04.02 - 15:08) #

If you're interested in the slow response idea, I'd suggest you take a look at the OpenBSD project's spamd(8), man page available at:

Some of the things it does:
- whitelisting
- blacklisting
- greylisting
- tarpitting
- stuttering

They've recently added synch'ing of the black/white databases between two spamd hosts, which makes for a nice failover solution, together with the likes of carp(4), not to mention pf's load balance capabilities for a large MX cluster.

They go to great lengths to make spammers hurt ;)

2 Colin (2007.04.02 - 23:14) #

Thanks, that looks like a lot of fun :)

3 Ronwen (2007.04.03 - 10:07) #


4 hugo (2007.04.13 - 21:00) #


My apologies, Lady Ronwen!


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