changing NAT from dynamic to static

Hi

I have a mail server that was using dynamic NAT from a pool of address.

I went in the firewall and create a static entry for the server.

But when I check on the server, it is still using the old dynamic address.

Is there a way to tel it to use the new static NAT without disabling/enabling the network or rebooting.

Or should I just wait, and eventually it will use the static entry

Thanks