-(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];
   
}

IOS正则表达式