For some mysterious reason, my company regularly receives solicitations from corporate sponsorship seekers from all over the country. The other day, for example, I received an unsolicited email from producers of a Thanksgiving parade letting me know that they've put their sponsorship packages "on sale," as if they were Walmart or Target. Thinking through the implications, it boggles the mind to imagine how many email and other solicitations corporations that actually deploy sponsorship must receive.
I've written before about why this sort of unsolicited, generic approach is a waste of time. Solicitations of nearly any sort by email, unless you have express permission to email the person, are counterproductive because they are so easily confused with (or lumped into the same categories as) spam.
Take a look at this video from the Business Marketing Association that my friend Bob Poole, author of Listen First Sell Later, forwarded. Revisit it every time you have the notion to mass mail, mass email, mass twitter, or mass anything about corporate sponsorship opportunities to companies you don't know. Mass mailing is not an effective tactic in your sponsorship strategy.