validates_format_of :email in database

I was forgot To apply
                               validates_format_of :email,

validates_format_of :contact_personal_email

This makes a lots of invalid emails of users . Now i fixed it on model
But the invalid emails now exists in my database (mysql).
Now i have to manually change the all invalid emails . but for this i
required a Report of all user have invalid email. (something in
migrations or find_by_sql)
I do not how to start this.

Please suggest .