HTML vs. bulk

> How much non-bulk mail does not contain a plaintext version of the
> HTML portion?

Very little.  But a lot of HTML-only bulk mail isn't spam.

Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://iecc.com/johnl, Sewer Commissioner
"I dropped the toothpaste", said Tom, crestfallenly.