Bulk Mail Services?
 

Is there such thing as legal bulk-emailing? And if so, what are the rules and who offers it?

It is called being CAN SPAM Compliant. Google it for the precise rules (ie: double opt in, opt out, snail mail address for opting out).

Depending on your record we offer it, but if you have no record, it would have to be on a test (or case-by-case) basis.