"To Whom It May Concern" is a letter greeting that has traditionally been used in business communication when there is no specific person to whom you are writing or when you do not know the person's name. The phrase was popularized in an article published in the New York Times on November 26, 1957. It can be used as a closing too. For example: "Dear Sir/Madam: Please find attached our proposal for your new project. We look forward to hearing from you soon regarding this opportunity." This phrase should be used with caution because it could seem like you're ignoring someone important by not addressing them directly. In American English, the corresponding phrase is "Dear [insert name here]". In British English, the equivalent would be "Dear (Mr./Ms.) [name]" or simply "[name]." Note that if the recipient's name is not known or cannot be ascertained with certainty, then the simple word "Dear" should be used instead ("Dear _________"). Also note that if you are sending a private email to several people, then the "To:" field should reflect this (i.e., multiple recipients should be separated by commas). Finally, make sure that your email is readable and clear!