Questions a out moveout charges, (do/how) you respond to ex-tenants?

[Luke H.]

Hi all, hope all is well.  20 days after move out accounting letter sent, ex-tenant sent email asking about the charges on the move out.  He thinks the charges are too high, that he wasn't responsible for some items, and think I am updating the house using the deposit. He did get money back.

-Some feedback, or general response would be greatly appreciated.
-Do you all send pictures and/or receipts ?
-Am I even legally obligated to respond to them?

And here I thought I was being fair and not over doing it.
Thanks for any help on this.