1) People aren't allowed to Private Message "against the rules" help to people either, it doesn't only extend to posting on these forums. Publically stating/asking for help in PM or via email is lame too.
2) mIRC has an inbuilt File Server, and inbuilt DCC support, I don't mind obviously but there's not much reason to specifically use XDCC.
3) If someone can't DCC send then it could be for a whole host of reasons, see
this thread. Firewalls/routers -> no/wrong port configuration is the most likely reason.
Regards,