There is no cell reception inside the building where I work so if someone calls and leaves a voice mail I don't find out until I'm driving away from work. Is there any way to get an email notification (or just a notification) when someone leaves a voice mail? I don't need the audio, just something that says I received a call. I'm with Verizon on an iPhone 6 running iOS 9.
Adopting a Google Voice number would allow you to do this, but only for calls placed to your Google Voice telephone number. It will also allow you access to SMS (non-iMessage) messages to that number.
This is definitely not a free option but have you considered (or do you have) an Apple Smartwatch?
You can connect a smartwatch to your phone by connecting to your wi-fi in your building (if you can leave your phone in your car or somewhere safe, get service and connect to the wi-fi that is). This way your phone can be picking up the calls and transfer the information to your smartwatch. Probably not the prefered action, but I believe it is the only way you can really do what you are asking. Verizon does have email notifications through FiOS Digital Voice, but that is only for home phone lines (as far as I can tell).