Go to settings in Mitel mobile program and go to call routing.
Click change on no other phones will simultaneously ring
Click top select number
Enter a description such as cell phone and your cell number and the number of rings to try somewhere between 4 – 6 but less than what your desk phone
rings
Click press 1 to connect and change it to connect automatically
Click save button
When complete, it should say incoming calls are routed to your desk phone and simultaneously ring your cell phone
The rings before incoming calls should be greater than rings on cell phone so your desk phone is one recording the voicemails.