Wash. Admin. Code § 504-26-035
Service of all university notices under this chapter is sent by electronic mail addressed to the party's university-issued email address or, if the party does not have a university-issued email address, to the email address on record with the university. Service is complete when the email is sent to the email address. Service may also be accomplished by personal delivery or regular U.S. mail. Notifications via regular U.S. mail are sent to the party's last known address or the address on file with the university registrar, and service is complete on the date the notice is placed in the mail. The student is responsible for maintaining an updated mailing address on file with the registrar. Recognized or registered student organizations are responsible for updating their mailing address on file with the center for fraternity and sorority life, university recreation, or student involvement. Deadlines described in this chapter begin the date the notification is sent via email, personally delivered, or placed in regular U.S. mail.
Wash. Admin. Code § 504-26-035