I've run into this before, and the simplest thing is to forward mail from two of the POP accounts to the third one, and use only one Location Document within Notes itself. Otherwise important email can be overlooked for a day or so, if you forget to change Locations on a regular basis. A Lotus Script could accomplish this in a (mostly) automated fashion, but that breaches system security to some degree and I would avoid that route. Simple is always the best.