Is my boss reading my emails?

Well, I don’t know about your specific situation, but yes, your employer can (and probably does) read your emails.  Don’t stop writing that personal email to your illicit lover just yet, because more than likely, your boss has better things to do than read all your emails.  Most companies employ software that scans network traffic, including your emails.  This software can detect what traffic is email and then scans for words/phrases that may be sensitive (e.g. intellectual property), bad (e.g. cuss words), or threatening (e.g. I’m going to bomb the Adderson office next Wednesday).  These emails are flagged and only these emails really get read by humans to determine what to do next.  My personal mantra is to not write anything on work email that I wouldn’t want posted on the front page of the New York Times.