In Thiara v. Pacific Coast Khalsa Diwan Society (2010) 182 Cal.App.4th 51, the respondents sought to dismiss an appeal based on the running of the 60-day time limit because they mailed a copy of the judgment to appellant with a cover letter, but without a proof of service. They argued the cover letter accomplished the same purposes as a proof of service and therefore should trigger the 60-day period. The Court of Appeal disagreed, refusing to disregard the clear and unambiguous requirement in the court rules for a proof of service, which proof could not be waived. "We do not believe a party should be required to speculate whether a cover letter accompanied by a copy of a judgment mailed to the party's attorney was intended to or did constitute a '"Notice of Entry" of judgment or a file-stamped copy of the judgment, accompanied by proof of service,' sufficient to commence the running of the time for filing a notice of appeal under rule 8.104(a)(2)." (Id. at p. 58.)