I am looking for some help in what to tell our GRID (SWGfl) who manage our firewall.

Currently our MDaemon server is accessible from outside the LAN:
A firewall rule was setup by our GRID which means users can acccess Worldclient from home if they point their browsers to:
WorldClient
it directs them to our internal IP address and port for worldclient.

I have some teachers who wish to use an IMAP client on their iphone and we've tried the instructions here:
iPhone IMAP Client Setup for MDaemon Mail Server

However it fails to connect to our server, which I am guessing is because the only public facing IP is the one that maps WorldClient to the worldclient port.....and that we need to open up another hole in our firewall to allow iphones to connect direct to our mdaemon server.

If this is correct what exactly do I need to tell our GRID to get the firewall rules changed?

Many thanks.