Regardless of whether or not it's technically possible to open resizable windows in full screen mode (and it is), the whole philosophy behind full-screen is to use a single window interface to remove and reduce any possible distractions. Like it or not, we are moving towards a single focused task as opposed to multi tasking. This gels better with how our brains are wired and actually makes us more productive than having to juggle many tasks at once.
If you need to refer to underlying emails, the option is of course there to NOT use full screen mode should you wish to do so. It's not *that* much different if you have mail expanded to fit the full screen in the first place.
If you need to refer to underlying emails, the option is of course there to NOT use full screen mode should you wish to do so. It's not *that* much different if you have mail expanded to fit the full screen in the first place.