What is the test for timely filing of a Notice of Appeal in a criminal case?

^2. The notice of appeal was signed on May 7, 2019, postmarked on May 10, 2019, and was "State Prison Generated Mail." "The prison-delivery rule ... provides that a self-represented prisoner's notice of appeal in a criminal case is deemed timely filed if, within the relevant period set forth in the California Rules of Court, the notice is delivered to prison authorities pursuant to the procedures established for prisoner mail." (Silverbrand v. County of Los Angeles (2009) 46 Cal.4th 106, 110, fn. omitted.)