dude, that name could go either way...in fact, iirc most chinese names don't denote gender. My sister and I have the same surname (Liu), and the same middle name (Hsien) that comes from some list that's repeated every half dozen generations or so, but the last characters in our names (Fei and Shuen) were picked by our parents b/c they sounded nice or for some random reason. So, can you distinguish between Liu Hsien Fei and Liu Hsien Shuen?
Sorry for the OT little spiel, imo just address it "Dear Yen Lam",