Never address your letter using “Dear Sirs” or “Gentlemen.” Always use the formal name of the person, along with their job title, in the address block, and use the appropriate form of address and last name in the salutation (Ms., Mr., Dr., Professor, etc.).
Don’t use “Miss” or “Mrs.” unless you have received some type of correspondence from the person and can see in writing which form of address they prefer. Always use “Ms.” unless you are absolutely certain she prefers something else.
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