Use java mail 1.4.7 (instead of 1.4 from 2006)

There were many fixes and enhancements from 1.4 especially related to SSL.

http://www.oracle.com/technetwork/java/javamail/javamail147changes-1917780.html
Signed-off-by: Alin Dreghiciu <adreghiciu@gmail.com>