"imagent" process eating CPU and memory

Hey everyone!

Today I had an issue with my 2012 13" Air running OS X 10.8.1. I only had Safari and Mail open, when suddenly the fans kicked in and the Air started to heat up. I noticed a process in Activity Monitor called "imagent" which was eating about 30-40% of CPU, and did "force quit" on it and the Air started to cool down. However I noticed that around 20 GB of my SSD space were gone. This was solved with a reboot.

I have found many issues like this, "imagent" process eating CPU and swapping to SSD. But what is this thing? Which app is it connected to? How to prevent it from doing such stuff in the future?

Thanks!