Service using RCW 4.28.080(17) is fraught with danger. In general, it should only be used in rare circumstances where no other possibility presents itself. It is often referred to as a P17 service or section 17 service.
As with any manner of service, use of P17 is dependent on the exact circumstances in which it is used. Unfortunately, there is very little case law from which to draw guidance.
It first came into being as the use of private mail receiving services (also known as PMB’s or mail drops) grew in the 1980’s and 1990’s. The idea being that if people were “hiding” behind a mail drop then, given due diligence to locate them, service of a summons should be allowed by presenting the documents to someone working at the mail drop or any other place where the defendant maintains a “usual mailing address.”