Wash. Rev. Code § 19.150.040
(1) When any part of the rent or other charges due from an occupant remains unpaid for fourteen consecutive days, an owner may terminate the right of the occupant to the use of the storage space at a self-service storage facility by sending a preliminary lien notice to the occupant's last known address, and to the alternative address specified in RCW 19.150.120(2), by first-class mail, postage prepaid, or electronic mail [email] address, containing all of the following:
(2) The owner may not send by electronic mail [email] the notice required under this section to the occupant's last known address or alternative address unless:
[ 2015 c 13 s 2; 2007 c 113 s 2; 1988 c 240 s 5.]