Dear Dr. Boli: When I was in high school, which happened in a different millennium, our English teacher taught us that the proper salutation for a business letter addressed to a party of unknown gender was Dear Sir or Madam. But that seems a bit limiting in our modern world, and I was wondering whether you knew what the proper up-to-date salutation for such a letter would be. —Sincerely, Mrs. Clank, English teacher at Blandville High.

Dear Madam: You are correct that the old salutation is no longer adequate. The correct up-to-date salutation for a business letter addressed to a recipient of unknown gender is Dear Sir or Madam or Whatever.