Reject Incoming Mails When System Load Is High

If you want your exim mailserver to reject incoming mails based on your system load then you use the smtp_load_reserve option of exim.

For Example :

If want to reject incoming mails if system load avarage is greater than or equal to 5 then edit exim.conf and put :

smtp_load_reserve = 5

save exim.conf and restart the exim server.