With [c] a spam filter
see:
http://www.nytimes.com/2012/09/20/business/seeking-revenue-p...
The US tax payers effectively subsidize an agency that delivers junk mail and there's nothing you can do to opt out of that junk mail if they buy those services from the USPS. Oh and the USPS still loses money doing it. I wish I could borrow from the Fed at 1.2%.