Maybe its worth looking at fail2ban to manage either the firewall or a block list that exim can use (I would prefer the latter since it then means that there is some log data that can be used at the point where your most important customer asks why you are blocking their mail).
Remember that all of these things can run in to the laws of unintended consequences. Its probably also possible to do something interesting with rate limiting. Fail2ban is at http://www.fail2ban.org/ Nigel. -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
