RCW 19.190.050: Blocking of commercial electronic mail by interactive computer service—Immunity from liability.

(1) An interactive computer service may, upon its own initiative, block the receipt or transmission through its service of any commercial electronic mail that it reasonably believes is, or will be, sent in violation of this chapter.

(2) No interactive computer service may be held liable for any action voluntarily taken in good faith to block the receipt or transmission through its service of any commercial electronic mail which it reasonably believes is, or will be, sent in violation of this chapter.