Paweł Leśniak wrote:
The worst is I also have ~500 IPs which I can't tell from logs (sender, recipient, ip, helo)whether I want those messages or not.
They will filter themselves for you. Legitimate MTAs will retry dozens to hundreds of times in 24 hours; however, zombies will only a try few times--most only once or twice. If you run daily reports on your logs, the worst case is a 1-day delivery delay for a very small amount of legitimate email.
