At least when left alone in idle.
I don't want to point fingers either, but if there is a piece of sw we ship that I wouldn't trust to let running all the time, it is the built in email client.

We do only this much of testing and in the wild there can be some funky setup which will trigger execution paths we never dreamt of.

I would have rather preferred a setup where we would have been using a local MTA like postfix and a web based MUA like sqirrelmail.