Perhaps at one point in time, it was acceptable to start any letter or e-mail with “To Whom It May Concern.” Starting your cover letter or e-mail for a job this way might give off the impression that you didn't do your research on who you're writing toAfter all, people who address other people by their names when writing and speaking to them tend to be more pleasant.
It can be used in letters of recommendation or reference, formal complaints（抱怨）made to a company, letters of introduction, and letters of interest.
Grammarly uses the example of needing to write a letter of recommendation, for a colleague who will have to make several copies to distribute to interviewers“In most cases, though, try to narrow your focus rather than cast a broad net,” notes Grammarly.”Ask yourself. Who does this e-mail concern? If you can honestly answer 'Anyone, 'then feel free to use “To Whom It May Concern.” （These are the things you should never say in your cover letter.）
If you do happen to find that using “To Whom It May Concern” is appropriate, don't make grammar mistakes, for example, letters or punctuation.
A. However, it maybe interesting.
B. Those times have changed, though.
C. Making mistakes in writing will surely get you low scores.
D. It's also very impersonal, which some employers might not appreciate.
E. In that circumstance, sending and receiving letters is more of a formal greeting.
F. You might want to take note of other common errors you might be committing, too.
G. But according to Grammarly, there are four times when it's OK to use this greeting.
