Hi, I just had a problem with a user that was sending 10000 emails via his Outlook at once and for me there was no way to stop it until they complained that Gmail just blocked him. Interestingly enough he didn't end up in any blacklist. I suppose this is becoming bigger and bigger problem for everyone out there - the bottom of this is being aware or stop the emails to be sent out at first so all these topics could be avoided: https://www.howtoforge.com/community/threads/hotmail-blocks-email-sender-id-record.79148/ https://www.howtoforge.com/community/threads/gmail-doesnt-like-me.78711/ https://www.howtoforge.com/community/threads/mail-question.78135/ https://www.howtoforge.com/community/threads/monitoring-outgoing-emails.78705/ Can you guys recommend some tool with step by step tutorial that is easy to implement on top? https://www.howtoforge.com/tutorial...8-4-jessie-apache-bind-dovecot-ispconfig-3-1/ I would need either limiting emails sent per domain or per mailbox or at least some sort of notification when a domain and/or mailbox goes above certain threshold, now it's really a "free for all". Any help is very much appreciated.