[Spambayes] Spam vs time-of-day

[Guido van Rossum]

> Attached is a plot of # of spams sent per 10-minute bucket (based on
> Skip's Date header cracking), vs time-of-day, across my subset of
> BruceG's 2002 spam collection.  The idea that *his* spam is mostly
> sent overnight is clearly bogus.  Someone who stops looking at email
> at 5pm and doesn't look again until 8am could sure get that
> impression, though.
> 
> The wiggly red line is a one-hour moving average.  An obvious
> conclusion is that many spammers have day jobs, and send out huge
> spikes at the beginning and end of their lunch hours, but struggle
> with software problems in between -- IOW, they're us <wink>.

The Date header reflects local time at the spammer's box, right?
Could it be local time on a box to which the spammer connects to send
his mail?  And would that box necessarily have the same local time?

In the graph, is there a difference between the narrow black bars and
the slightly wider blue/gray bars with black outlines?

--Guido van Rossum (home page: http://www.python.org/~guido/)