Prevent auto retrieval of e-mail when opening Mail in iPhone: is it possible?

Prevent auto retrieval of e-mail when opening Mail in iPhone: is it possible?

Whenever I open the standard iPhone mail client, my mail is automatically retrieved regardless of the "manual" setting in my email settings. Since I have multiple e-mail accounts configured, this can be a very timely process and with the lack of a read all function, this is really a pain.