We are looking to move from an old Analog PBX to 3CX and have purchased a 3CX license to test out. Our old PBX system had 3-digit extensions and we will utilize 4-digit extensions on the new system. To help ease the transition we are putting the old 3-digit extension in the "SIP ID" box to accept calls from both the old and new extension. For example, let's say "Joe Smith" has extension 320 on his current phone but will have "4000" on his new 3CX phone. If I put 320 in as his SIP ID, someone can call 320 and still ring through to his new extension. This works for calls internally; however, from the Digital Receptionist, these 3-digit "SIP ID" extensions don't work. The digital receptionist just repeats itself. Does anyone have any suggestions on how to have this work from external trunks through the digital receptionist? I would like to ease people off of their 3-digit extensions as many people have business cards printed and/or outside contacts that won't know the new 4-digit extension for some time after the transition.