Why are you afraid that politeness will slow you down?
When you walk in to a store and you wish to place an order '1" wrench' is probably as compact as it gets. But 'I would like to have a 1" wrench please' is the normal form and even though it takes slightly longer typically you'll get a better response. You give the recipient a feeling of being appreciated, even though in the strict information theory sense there is nothing added to the conversation.
Those few words are the idiomatic way of asking for something and since email is similarly unconstrained in space (as opposed to say SMS text), has its roots in traditional letter writing, and is very easy to write people have settled on a form that is somewhat more compact that a regular (dead tree) letter but still long enough that it carries a sense of old-fashioned politeness. Typically this includes a salutation at the top and a signature at the bottom of some sort (usually a standard file).
Of course you are free to leave all of that stuff out, but if you write me 'give banana' without any introduction or explanation the only place where your 'instant' email is going to go is the trash bin. So all that flowery stuff actually increases the chances of the message making it through by using a slightly less compact form.
Greetings and much good luck with your quest for efficiency.
Your truly,
Jacques Mattheij