Perhaps at one point in time, it was acceptable to start any letter or e-mail with “To Whom It May Concern.” However, those times have changed—and 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 contacting. It’s also very impersonal, which some employers might not appreciate. (After all, people who address other people by their names when writing and speaking to them tend to be more charming.)
But according to Grammarly, there are four times when it’s actually OK to use this greeting: in letters of recommendation or reference, formal complaints lodged with a company, letters of introduction, and letters of interest or prospecting.
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 that circumstance, the correspondence is more of a formal greeting. “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.” (Here are some 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 the grammar mistake of not capitalizing every letter and leaving out the colon. (You might want to take note of these other common grammar mistakes you might be making, too.)