Indeed, I found that deleting the entire HKCU/Software/Classes/CLSID restored the functionality of the e-mail app and Bing app links to IE10. However, I was afraid that this fix might be too extreme. So, I backed up the key, and the deleted the CLSID individual keys in groups to find the offending group. I started with all keys beginning with "1" all the way through "F". I found it was the group beginning with "8". So, I restored the original complete HKCU/Software/Classes/CLSID key, then deleted each individual key beginning with an "8".
It ended up being {871C3580-42A0-1069-A2EA-08002B30309D}.
I have no idea what program created this key. I Googled it to no avail. Most likely something leftover from my Windows 7, upgraded from Vista, upgraded from XP, etc., or perhaps some kind of trojan?
There may be other keys that would cause this problem, but it only took about an hour or so to find the offending CLSID key. Just a suggestion for those who might be "chicken" like me!