Yeah, most Senators have a number of people known as "Legislative Correspondents" or "LCs"--a paid (well, barely paid) position with the job of researching certain topics and answering constituent emails about them. Getting from an LC to a Senator is tough. Your best bet is a phone call.

Of course it is. But if he/she responds to hundreds of people who e-mailed to complain about SOPA, I bet the senator would hear about it...