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I'm writing a formal appeal letter as a reply to a letter I got from a government agency. Unfortunately, the person sending it only put their name with an intial, e.g. "J. Smith" and no title. They're in a foreign French speaking country, and I don't want to be too informal.
What would be the correct way to address them in my reply? "Dear Sir or Madam", "Dear J. Smith"... any suggestions?