IdentityOptions.User.RequireUniqueEmail setting seems to be ignored.

[braveyp]

My initialisation code for Identity is something along the lines of:

var builder = services.AddIdentityCore<ApplicationUser>(options =>
{
    options.Stores.MaxLengthForKeys = 128;
    options.SignIn.RequireConfirmedAccount = true;
    options.User.RequireUniqueEmail = false;
    configureOptions?.Invoke(options);
});

When I try and create a user with a duplicate email address (but different username) I get an error that the email address is already taken. I did note that the mysql schema at least has a unique constraint on the email column which is the first issue.

[beginor]

Just remove the constraint from aspnet_users table.

[braveyp]

That's the partial workaround yes. A more complete one is to change it from a unique index to just a key index to avoid performance issues with user lookups by email.