You might also consider giving them the option to skip your voicemail message completely by pressing another key (again, check with IT). You also want to make callers aware what you will return their call, instead of telling them that you will try to return their call--and let them know when you are likely to do it, if possible. If necessary, provide additional or emergency information in your voicemail greetings. My dentist, for example, lists his cell phone number for emergencies.
3. Use a male-to-male headphone cable (that is, one with connectors at both ends) to connect your phone to your computer’s “Line In” jack. That cable shouldn’t run you more than a few bucks. Note that some computers, particularly Macs, only have one audio port that serves as both input and output.

You would think there'd be app for that, but Apple doesn't allow third-party apps to access the microphone and the integrated Phone app directly. However, there are tricks within some apps and services to get around that limitation that can make you a mobile wire-tapping master.
Professional voicemail greetings for your business cell phone number It’s a good practice for each of your team members to have their own personal business phone numbers. There are many reasons why they shouldn’t use their personal cell phone number for business , so you’ll want to give them their own phone number through your VoIP