How block connection from other jabber server?

Hello it is posible somehow block other servers conecting to us using blacklist or something?
We are under spammers atack(messages incoming to your accounts on your server), but they dont have account on our jabber server it is comming from foreign servers.

Thank you for hints.

Frantisek

Check out the Admin Console on Openfire 4.0.1 https://localhost:9091/connection-settings-socket-s2s.jsp Server -> Server Settings -> Server to Server

That is it! wow its easy , thank you very much.