Doesn't the CAN-SPAM act make it legal to send unsolicited bulk e-mail?
No, it doesn't. In fact, the United States federal law known as the "CAN-SPAM Act of 2003" explicitly allows service providers such as Tiger Technologies to set their own strict anti-spam policies.
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.