Can I borrow some MTA address traces?

John R. Levine johnl at
Sun Mar 30 16:09:12 UTC 2014

As noted about a zillion messages ago, one of the concerns about IPv6 mail 
is whether DNSBLs will be workable, with one of the questions being 
whether the lookups will blow away DNS caches.  As far as I can tell, 
there is basically no research on DNS cache behavior other than a few very 
old papers that said for normal loads, a reasonable sized cache is big 
enough to work.

For the DNSBL stuff I'm doing some simulations, which need data to drive 
the lookups.  The data is really simple, a sequence of pairs:

[ IP address, timestamp ]

IPv4 traces are currently more useful than IPv6, since v6 doesn't have the 
botnet traffic that makes the DNSBL lookups interesting.

Traces from medium sized systems, say a million connections a day, would 
be great.  If you consider the IP addresses confidential you can hash 
them, although real ones would be better so I can test tweaks that treat 
known high volume senders (gmail etc.) differently.  Thanks.

John Levine, johnl at, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail.

PS: I hope it's OK if we take a break from reinventing patented anti-spam 
techniques that have failed repeatedly before to talk about something 

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