SoftDelete和unique_index冲突

I would like to store an email address in my table users and be certain that this address is not already present, for that I chose the parameter unique_index, by congress if a user removes his account and wishes the create it later, it can not because the unique_index message is displayed while it isdeleted_at.

Do you know if there is a better method with Gorm to treat this case?

type User struct {
    Base
    Name     string `json:"name" gorm:"name;"`
    Email    string `json:"email" gorm:"email;unique_index"`
    Password string `json:"password" gorm:"password;"`
}

to add :

user := new(model.User)
[...]
db.Create(&user)

Thanks for your help