Doesn't the CAN-SPAM act make it legal to send unsolicited bulk email?

The United States federal law known as the CAN-SPAM Act of 2003 sets out a list of certain things that are explicitly illegal to do when sending bulk mail.

Some people think this means that email companies are required to accept any bulk mail that doesn’t violate the law, but that’s not the case. In fact, the law explicitly allows service providers to set their own stricter anti-spam policies:

8(c) No effect on policies of providers of Internet access service

Nothing in this chapter shall be construed to have any effect on the lawfulness or unlawfulness, under any other provision of law, of the adoption, implementation, or enforcement by a provider of Internet access service of a policy of declining to transmit, route, relay, handle, or store certain types of electronic mail messages.

The spam policy we have chosen completely forbids the sending of unsolicited bulk messages. All reputable service providers use a similar policy. This policy is a legally binding part of the contract our customers agree to when they open an account with us.