That is what I was thinking.
Do you think it could be a good idea to implement it ?
Also, I've been unbanned since I'm using in main.cf of postfix :
Some of they are quite usefull and easy to deploy (checks and blacklist), would it be a nice idea too to implement these ? (at least the checks)
here's the relevant parts of my main.cf :
smtpd_delay_reject = yes
smtpd_require_helo = yes