One of the tools in any system engineer’s hand as well as those dealing with customer remote service is to set a remote connection to the other end’s server or PC, through VPN, Public IP or any other possible way. One easy yet effective approach is to establish a ssh tunnel by means of reverse SSH.
Here is the simple postfix configuration to make it work with freepbx.
Based on a customer request, we needed to have some virtual extensions (Voice Mail enabled) but the problem was that they wanted the incoming calls to extensions to ring 4 times before falling back to voice mail. Since by default FreePBX will get the extension status as UNAVAILABLE and I couldn’t get virtual extension running with this version of freepbx, i did this trick: