"Dear Writer: Thank you very much for your query, and my apologies for having taken so long to get back to you. I'm afraid that, although under other circumstances I might want to take a look at some of your work, I am swamped with submissions and current commitments at the moment, and so I'm simply not able to consider your project right now. However, I do appreciate the opportunity to consider your writing, and wish you success in finding the right person to represent your literary interests. Sincerely, Sam Stoloff"
Note how politely tentative he is: he might want to look at some of your work under other circumstances. But he is swamped and overcommitted. In the end, you kind of feel sorry for him that he's not going to get to read your amazing novel. Now, that is really quite classy and brilliant. Well played, Mr. Stoloff. I wouldn't mind seeing one of your more personalized rejections. Can any one help out on that?