Hi, I found much of convenience on 3CX, but I have a problem that's cannot make calls to another external PSTN numbers. The internal-to-internal calls are all ok. Is there any mistake in my Outbound Rules or other related configurations? Outbound Rules: "Calls to Numbers starting with" I specified "9" "Transform mask" I specified "r" Can someone help me? I'd like a particular instruction, if can. Thanks & Regards, Sonlm.