in mail 8.2 if I click the template button the CPU start running at 150% CPU and WindowServer arrive to 20 GB and more of memory

hello, after upgrade to Yosemite I have a problem with Mail/CPU.

if I create a new email message everything is ok, but if I click the button at the top right (show template) on the message window, the CPU running at 130-150% and the VirtualServer memory start increasing up you 20 GB and more.

If I close and reopen Mail (without closing the mail message) the CPU return to 130-150% but if I send or delete the message the CPU return to the standard value

If I don't click the template button on the new message window the CPU works correctly.

This thing cause slowdowns and unexpected logout of my imac, I contacted applecare twice and they told me to create a new user (first) and reinstall a fresh operating system (second). I have done both but the problem is not solved.

I have also tried this (without results): Guide: How to solve Yosemite memory leaks and CPU usage

Do you have any solution for may problem?

imac 5K - 16 GB ram

Yosemite 10.10.2

Mail 8.2

Thanks in advance