Did you check out the user messages plugin?

Wouldn't just about any "Contact Us" plugin fill the bill? There are literally dozens of them.

yes i checked out users messages plugin. But that would enable users messaging each other. I wanted a USER to messages ADMIN only.


I wanted a conversation between user & admin. Contact us plugin might only allow users to give their email id & leave their message. I wanted a plugin where a user who has already signed up for my website & wants to message admin. And admin should be able to reply him back. That's what my clients requirement is unfortunately.

are these private, or publicly visible messages?

If private, why the aversion to email?

If public, maybe just use the moderated comment feature.

Or if the point is threaded conversations, maybe install phpBB and use that?

I don't know if you'll find anything pre-built out there.
If you don't want to build something from the ground up your best bet would probably be the user messages plugin, I imagine it wouldn't be to hard to add a conditional statement in the code that would only allow sending messages to the "admin" user.

I already did that