I have a new server with a private IP address only and a firewall that forwards traffic on a Public IP address.  All the appropriate ports are open and we are able to receive emails from the outside world.  The problem is connecting with Outlook, Iphone or other email software through IMAP.  I can get it setup fine on the Private Network, but am blocked when sending through SMTP from anywhere public.  I have checked the firewall and the traffic is being forwarded properly, but iredmail is not allowing it for some reason.  I suspect I need to tell iredmail to allow SMTP traffic from the public realm or something.  What am I missing?