You're awesome. Thank you!!
My name is [name] and I sent out a query/partial/full for [novel] on [date] and I am wondering if you have recieved it/had time to read it/had made a decision/whatever your reason. Thank you for your time and I hope to hear from you soon.
I think that is fairly basic. You don't have to get too fancy but always make sure you include your name, the title of your book, and the date you sent it out on. Makes things easier to find.