Before 1962, there were several local post offices throughout the town of Southeast, located near larger concentrations of residences and businesses. The last of these, Southeast's Putnam Lake post office, closed in 1968. When a new post office opened at 16 Main Street in Brewster on July 17, 1966, even before Interstate 84 and Interstate 684 were constructed, it was named Brewster and given the zip code 10509. The two highways brought massive population increases, nearly tripling the number of residents in Southeast in a matter of about 20 years. As a result, "Brewster, NY 10509" was part of the return address of every resident of Southeast and Brewster. Probably because of the proximity to the Brewster train station, the highway exit signs of I-84 and I-684 say "Brewster". Road signs in White Plains, Danbury, Carmel and other nearby towns all direct travelers to Brewster. Only the town's "Welcome to Southeast" signs acknowledge the town's existence.