My idea is reduce the file size of SEPM report at the version 14.2.
From 14.2, the file size of report e-mail in SEPM is increased more than six times compare to 14.0. ( from 86Kbyte to 555Kbyte ).
Increased file size of report will consume mailserver storage and Smartphone data plan, take more time to open and read mail client.
Technical Support answer is, due to product enhancement to display pie chart on the report, there is no way to reduce the report size.