Yesterday i set up some e-mail accounts and a domain. everything looks fine en works for as far as i can tell. Now i was wondering... do i need to set some blacklists or something to prevent my mailserver from sending spam? i checked the log: mail.log and i noticed that there are bots trying to send without authentication... and a few that tried to login with generated passwords and usernames... so far i guess no problems... from this log i think thy cant login so not send anything... but the fact that there trying... i would think there is a blacklist somewhere to even prevent this from happening... or at least the mostly used addresses or something ... i dont mind that there trying but i just want it to be safe
These trials are normal and your server runs a software (fail2ban) that blacklists such attempts automatically after a few failed password retries.
