We are using Version 10 SP3 with Exchange 2010 UM for voicemail. I have setup the "Play on Phone" feature just as described in the 3CX blog and it works -mostly. Here is the issue: Every 7 days the UMWorkerProcess on the Exchange Unified Messaging server recycles itself automatically. When it does this it changes the port it uses. It alternates between 5065 and 5067. Week 1 = 5065 Week 2 = 5067 Week 3 = 5065 Week 4 = 5067...you get the idea. When setting up the "Play on Phone" (as a Generic SIP Trunk) you specify port 5065 but when the UM server changes to 5067 the feature no longer works. I have to manually change the port in 3CX to match the UM port for it to work again. So, I'm looking for a way to work around the issue by automating the port change in 3CX. Is there an xml or other file where the port information is kept that could be changed to match the UM server port? I'm hoping to write a script that will monitor the UMWorkerprocess port and update 3CX when it changes. I just need to know if the setting for a VOIP trunk can be changed in a file. Any ideas? (does it even make sense?) Thanks!