On Fri, 22 Sep 2017, Davide Marchi wrote:
Is there any way to tell to reject any mail coming to the MX backup server, if the primary server is up?
Won't that make the secondary MX fail its purpose, which is to quickly serve incoming legitimate mail if the primary is down ?
We have had since ages two MX, and since years we are effectively filtering spam *mainly* by greylisting (*) ... but that implies the two MX are peered for what greylisting is concerned.
(*) which does not mean SA is useless, as it was demonstrated recently when an OS upgrade temporarily disabled amavisd (which is what triggers spamassassin) and the SA-filtered spam came through. As an order of magnitude, graylisting filters 80-85% of incoming mail. The rest is about 50-50 ham and spam.
-- Lucio Chiappetti - INAF/IASF - via Bassini 15 - I-20133 Milano (Italy) For more info : http://www.iasf-milano.inaf.it/~lucio/personal.html ------------------------------------------------------------------------ Nature (http://tinyurl.com/natureaboutrenzi) 09/12/2016 says: "Italian scientists won't miss departing Prime Minister Matteo Renzi"
