Although dear can come across as stuffy, it's appropriate for formal emails. Use it when you're addressing a person in a position of respect (e.g., Dear Lieutenant Smith) and in formal business missives such as a résumé cover letter.

用dear作为邮件的开头是没问题的，但是很多人会忘记在后面加人的名字，正确的用法是：

• Dear Adam, ...

• Dear customers, ...

大家可能认为“dear”是表现关系亲密的一种打招呼方式，实际上在外国人眼中这个词很stuffy：

• Stuffy: 一本正经的

• Too formal: 太正式

所以“dear“适合用在一些比较正式的场合，表示对他人的尊敬：

• Dear Mr.Smith, ...（后面可以加姓也可以加名字）

In all but the most formal settings, this email greeting is the clear winner. It's simple, friendly, and direct. If you want a slightly more formal tone, consider replacing hi with hello.

“Hi”没有“Dear”听起来那么正式，适合用在对方和你有一定关系的场合：

• Hi Jenny, ...

而“hello”的正式程度介于“Hi”和“Dear”之间，但是还是“hi”更常用一点。

• Stand out: 突出

• Unobtrusive /ˌʌnəbˈtrusɪv/: 不唐突的

This one bridges the gap between the breezy hi and the more formal dear. It's used less often, though, so be aware that it might stand out, and don't use it if you want your greeting to be unobtrusive.

If you're addressing a group of people, this is the way to go. We prefer it to more abrupt greetings like "All," or the too gender-specific "Gentlemen" or "Ladies."

如果给一群人发邮件，我们可以用：

• Hi everyone, ...（适合工作场合）

• Hey guys, ...（适合朋友之间）

  
  

如果一群朋友中没有男生，用"hey guys"就不太合适，可以用"hey grils/ladies"；但如果团体里面有女生也有男生，用"Hey guys"就没问题！ 

The advantage of Hi there is that it works well if you’re sending a mass email or using a mail merge feature with customized name fields.

"Hi there"在口语里也非常常用，会让别人觉得你很友善，比较适合用在陌生人之间，比如客服场景：

• Hi there, my phone breaks, ...

1.不要用Dear Sir和Dear Madam：

Have you ever read and responded to a letter that greeted you with Dear Sir or Madam? We're going to go ahead and guess you haven't. Not only is this salutation stiff and formal, it shows that you couldn't be bothered to look up a contact name and address someone specific.（这种说法非常过时，而且有点冒犯的感觉）

2.不要用To whom it may concern：

The same sentiments that apply to Dear Sir or Madam apply here. If your letter opens with To Whom It May Concern, we're probably going to assume it doesn't concern us.（这种说法过于正式，让人觉得很滑稽）

3.最后给大家发求职邮件一些小建议：

Don't use this greeting with job application cover letters. Make a point to find the hiring manager's name, even if that means calling the company and asking. If you can't find a name, "Dear Hiring Manager:"or "Dear [Company] Team:"will work.