http://murray.senate.gov/email/There is a form on this webpage. I just used it to relay my disgust at her having voted for amnesty for the illegal immigrants. After reading a bit more about the proposed bill, and how these criminals are going to receive a lot more benefits etc than any American, just couldn't contain my contempt.
Told her if she wanted to advocate for those from another country over, and against, the legal ones in this one, go there instead of staying here trying to ruin ours.