Mailscanner + postfix: dealing with huge loads on distributed mailserver setup
l at avc.su
l at avc.su
Sat Aug 8 21:46:34 UTC 2015
We've got 2 servers with MailScanner+Mailwatch, using Postfix as MTA.
Recently we've experienced huge incoming load from distributed locations
(our marketing team fired up large newsletter and our corporate server
got about 10K "auto-reply" mails in just 20 minutes), and our 'hold'
queue got filled up with mails. It caused big delay in recieving
legitimate mails, and MailScanner (15 children max.) was buisy with them
for about an hour.
Is there any way to prevent Postfix from recieving any new mail if there
is a clog in Hold queue? For example, if there are more than 500
messages, don't recieve new mail and respond with 421 code so clients
would go to another mail server?
I haven't found any solid measures against it, and I'm considering to
write own policy-server for Postfix. It's complicated task (and I'm lack
of coding skills), and I want to be sure that I haven't missed vanilla
setting for this.
So, basically, there two questions: is there some sort of failswitch to
prevent Postfix to get new connections if there is a clog in queue, and
how do you deal with huge mailing loads?
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