Once a client switches to the new Vuture/Dynamics integration (called Dynamics v2 here in this help desk), the naming convention on email Forms will change.

For this reason, all Forms in use will need to be upgraded.  This will be done for you by the Vuture team.  There is an article covering this upgrade here.

What is the difference?

The only difference you will notice is that field names on your forms will no longer be Dynamics_xxx.  Instead they will have no prefix, or start VxForm_xxx, as in the "before and after" image below: