Somewhere along the way, I quit using email greetings like "Dear" and fell into a pattern. If I don't know the recipient, I start an email with "Hi (John)." If I know the recipient, I say, "Hey (John)."

And if I've exchanged emails with the recipient but for some reason feel a slightly more formal approach makes sense -- if we haven't emailed for a long time, or the person's status makes me feel like "Hey" is too familiar -- then I stick with "Hi."

I figure I can't go wrong with "Hi." 

Turns out, research backs up my approach. According to Brendan Greenley, these email greetings generate the best response rate:

  • Hey: 64 percent
  • Hello: 63.6 percent
  • Hi: 62.7 percent
  • Greetings: 57.2 percent
  • Dear: 56.5 percent
  • All emails: 47.5 percent

While you might think that a five to eight point swing in response rate between "Dear" and the combo of "Hey" and "Hi" isn't significant, think again. If changing your greeting results in nearly one more out of 10 people responding to your emails -- whether you're cold emailing, trying to connect, or simply asking a friend for a favor -- it's definitely worth it.

And if you're a fan of "Dear," which is great for handwritten letters, in emails "Dear" sounds too formal. "Dear" sounds like the sender is about to ask for a favor. Or to apologize for a mistake. 

As Brendan writes, "Interestingly enough, research cites that formality tends to be higher when there's less shared context, as well as when speakers dislike each other, neither of which are ideal if you need a reply!"

So what should you do?

First, always include a greeting when you start an email chain. Any greeting performed better than the overall response rate for all emails. 

Once you're in response mode, it's fine to skip the greeting. If you and I have been emailing back and forth all morning, there's no need to say, "Hey, Jeff" every time.

Then, start your emails with "Hi," "Hey," or "Hello."

(If you're emailing me, don't use "Hello." It sounds like you're trying hard to be casual and professional, which means you're doing neither.) 

Use "Hi" for people you don't know well or haven't emailed in a long time. Use "Hey" for people you know well or have recently corresponded with.

And then make sure your next sentence isn't one of these, because that will make it much less likely for the rest of your email to get read, much less generate a response.