Rain or shine, slush or mush, the mail gets through — only it’s not the U.S. Postal Service that goes the last mile to your door, it’s Harvard Mail Services. The Gazette rode along with lead driver Danny Brainard, who started with Harvard’s mail office shortly after it was created in the late 1980s. Brainard’s day starts early and includes 85 or 90 stops and at least that many greetings and smiles.