Hi, I'm new in 3CX, and its amazing. My problem is: I want to make call FROM or TO phones out of the office(in different network) first of all my IP address is dynamic but I installed an application from noip.com that prefer a DNS and sync every 5 minutes with my ip address. second I set a port forwarding on my router.(translate port 5060 to 5060) third I install a 3CX with that FQDN and its successfully installed. I use 3CX to make a call ability to my clients with each other only so I haven't any sip trunk or gateway just after installation completed I tried to create an extensions and send invitation mail to my clients but it didn't works! Please help me. Thanks.