the model used to be with .mac mail: remote mail stored on Mac.com,all read portals e.g iPad, iPhone, outlook express on pc etc. set to read but don't delete from server. This to allow me to read on whichever portal was convenient and ensure all portals could see the email. Once a month I'd delete it from the server, to keep the server folds 'cleaned up'. Now I'm at a client site where I can't access iCloud.com from their machines (IT policy bars access to it) so I can't delete it using my iPad or iPhone and Safari, which I used to be able to do. Backwards step in usability/flexibility from Apple.