判斷郵箱格式是否正確的代碼

// 利用正則表達式驗證 -( BOOL )isValidateEmail:( NSString  *)email  
{  
NSString  *emailRegex =  @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}" ;  
NSPredicate  *emailTest = [ NSPredicate   predicateWithFormat : @"SELF MATCHES%@" ,emailRegex];  
return  [emailTest  evaluateWithObject :email];  
}