The methods of giving notice are by personal service, either actual or constructive, corresponding to an actual or constructive personal demand, by service at a place designated as the place of serving notices, or by mail, which is another kind of constructive personal service. Oral notices of dishonor can only be served, of course, in the first two methods. The cases in which notices can be served by mail are dependent upon the residences of the parties, unless the rule has been changed by statute. The natural order to consider the question is to first determine when notices can be served by mail, then the sufficiency of the service by mail, and then the cases of personal service.