Excerpt from this article:
My boss gets 500 emails a day. I try not to email her but sometimes I have to, and the one way to get her to reply quickly is simple: I start every email to her with a question. And then if needed, I explain the context to my question in one or two more sentences in the fewest possible words.
Starting with a question is important because if your boss scrolls through emails on her phone, like most of us do, her screen allows her to see only the first few words of an email before she chooses to reply, delete, or ignore it. Words like “Do you think…” or “Could we…” or “Will you confirm…” are quick shorthand phrases that tell her THIS IS AN EASY EMAIL. All she has to do is reply yes or no. And she’ll email you back faster.
Another great touch you can add while emailing your boss, co-workers, and especially people who don’t work at your company is changing every “can” and “will” to “could you please” and “would you.” At first you will worry you sound ridiculously formal: “Could you please tell me if…?” and “Would you consider…?” But then people will start being SO NICE TO YOU and MOVE MOUNTAINS to help you only because you SOUND like a very nice refined person with poise — even if you’re falling apart at your desk, even if they’ve never met you.