def smtp_response(code, lines):
    response = []
    
    for i in range(len(lines) - 1):
        response.append(b'%i-%s\r\n' % (code, lines[i].encode()))
    
    response.append(b'%i %s\r\n' % (code, lines[-1].encode()))
    return b''.join(response)

if __name__ == '__main__':
    print(smtp_response(220, ['ESMTP server at your service', 'SMTPUTF8', '8BITMIME', 'STARTTLS']))
    print(smtp_response(250, ['Ok']))