I noticed that more and more new users are inadvertently typing their emails incorrectly during registration, in turn the users are not receiving their verification emails to complete the registration process.
To prevent this from happening or at least minimize it, I have added a field in the registration form for the user to re-enter the email address much like the password confirmation. This will then force the users to enter the email twice to verify that it was entered correctly the first time.
I hope this helps!!!