OS X Yosemite is supposed to make Macs run more efficiently than ever, but some early upgraders have discovered a huge memory leak that causes memory pressure to skyrocket and productivity to drop.
The updated Mail app appears to be the culprit of the memory leak that is triggered whenever multiple files are dragged into an email to be added as attachments. Over 100 hundred users have confirmed the memory leak on Apple’s Support forum with screenshots of Mail hogging up to 24GB of RAM.

