Staying on top of messages that come into her inbox is part of how Sandberg is able to help manage a 20,658-person company.
"I would rather give a short, quick, incomplete answer than wait and do it better," Sandberg says.
Productivity and leadership coach Ellen Faye agrees that long email responses are usually a waste of time.
"First of all, whomever you're sending it to probably won't read the whole thing – they're busy, too," Faye tells CNBC Make It. "It will just cause them to put it aside until they have more time," or worse, until it's forgotten.
Although you might feel pressure to write a perfect email, you are likely to get your point across just as well by writing a quick, less-than-perfect email, Faye explains.
While it might seem impossible to answer all 100 emails you may receive every day, Sandberg says holding off until you can write a perfect response doesn't make sense.
"'Done' is better than perfect," she says. "People underestimate how opening up your emails again is so time-consuming because you read it again."
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