Rejecting potential models

[furrygirl]

Hello, I've been lurking and meaning to post. Here's something I'm pondering:

I'm working on a multi-person "alt porn" pay site. I have an open casting call on the site as it is now, and I have mostly been contacted by sexy people who sound really great to work with. Recently, I got a model application from a guy maybe in his 40s, not conventionally attractive, and just not the look I'm going for. (Especially for solo/softcore pics.) I feel bad saying no to someone because they don't fit my beauty standards, but I need to give this guy an answer.

How do others reject potential models? I'd love to see a sample form letter if anyone has a standard reply.