When writing to a member of Congress, the letter should be addressed with the designation "The Honorable" followed by the representative's full name. Within the letter itself, the salutation should read "Dear" Mr. or Ms., followed by the last name.
Mail sent to all government officials requires specific forms of address. A letter to a senator is addressed in the same way as a representative. However, the greeting begins "Dear Senator" and is followed by the last name. A letter to the commander-in-chief identifies "The President" on the envelope. The salutation does not include the president's name. It simply states "Dear Mr. President" or "Dear Madam "President."