MetaFilter has put together a nice collection of sites that estimate how much of all email sent across the world i spam. See for yourself

djo - 14 July 2004 [«« Reply to this]
But what's your personal spam load?

For myself, I estimate 20% spam. But if I removed the various mailing lists I'm signed up to, it would be more like 95%+
Peter - 21 July 2004 [«« Reply to this]
The mailing lists should not count because they've already been filtered from lots of spam so they are biased. My estimate (excluding mailing lists) is 75-80% spam.
Jan - 11 December 2006 [«« Reply to this]
MF now has 85% and I have seen 90% quote elsewhere. Botnets have been on a steep rise last 6 months, with 20% home computers in the U.S. alone expected to be zombies or otherwise compromised (theregister articles).

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