That's right. Also important, email is not a playground for experiments. Once it runs, you should not touch it anymore, except for updates. Otherwise, you will do harm to your own way of communicating. One error, and you will lose all your reputation and someone spams half of the internet with your domain as sender.
An when it runs, the only thing to improve is tuning the spam-filter for your instance. Implementing all the rules that you fight the other day, because otherwise your inbox explodes. So you have to do all the shady things and block ips, filter with blacklists and check every dns for all those extra entries, needed for delivering mail... You must become a part of the problem, spammers all behind every cracked wordpress and insecure vps out there.