When we have large events and high volume of online sales we get a tremendous amount of email bounce backs. (because guests enter a incorrect email address). We just had over 60 in one day and we had to call 60 people to get the correct email address. Webforms could use the upgrade of an email confirmation field, which is a very basic solution found on almost every website form on the internet
We have this same problem, 5 years later.
PLEASE VOTE FOR THIS FEATURE!!!!!!