How to let applicant know they were denied

[Yvonne H.]

I get a lot of applicants, escpecially from Zillow, that for any number of reasons--be it income, background, credit, whatever--they don't qualify. What do you tell your applicants when they don't qualify? I don't want to give reasons that are too specific and set myself up for engaging in dialogue. I don't want them responding back (why that is wrong, they've changed, they're working on improving their credit, that was their roommate...whatever, I don't care) 
How do you inform applicants when their application is denied?

TIA