Of course I can, and did. I have a YouMail contact that I use. I'm not as much concerned about my ability to get to my YouMail as I am about having my device restricted so I can't modify a setting like this. In other words, Verizon Wireless is so concerned that I'm going to screw up my ability to get to my voicemail that they are preventing me from changing the number. This just isn't necessary. Why can't I get this unlocked? It's my phone, right? I mean, I payed for it!