Tone Context Dear Formal and polite Standard, neutral greeting within the professional sphere. Hello Considered to be a standard greeting, more often used when the explicit purpose of your email is to introduce yourself to the recipient. Hi More casual and polite Generally unacceptable for a business email, unless both you and the email recipient work in a more laid-back and relaxed industry. Greetings to avoid: Hey: Too casual for a business environment Dear Sir or Madam/To whom it may concern: While tempting to use if you don’t know the person’s name, these phrases are overly formal and come across as too cold and impersonal.