Let's start by clearing up a misconception. Both D1 and D2 coaches may email a player beginning September 1 of the junior year. They don't have to wait until July 1. (Bylaw 13.4.1)
D1 coaches may not telephone a player until July 1 after the junior year. D2 may call on June 15 after the junior year. Either division allows the coach to answer phone calls at any time. (13.1.3)
D3 has no similar limitations.