A building in Greenwich had to be evacuated this morning because of a suspicious package. Police got the call around 11:00 am from One Greenwich Plaza that a worker in the mailroom opened a package containing a "suspicious" substance.  Police officers, the fire department and the bomb squad respnded in hazmat suits.  Samples of the substance have been sent to the state health department. Workers and two others in the mailroom have not shown any illness from exposure to the substance found there.