Postfix Tuning and steps to tune the postfix in server

How to tune the postfix in your server?

The probably the best thing you could do is to write the logs to

another syslog server as is done in this syslog.conf snippet.

mail.* @xxx.xxx.xxx.xxx

or if you can't spare a machine for that, put dash in front of the

filename. Default behavior of syslogd is to sync the logfile after every

change. Testing before and after, this dropped my load average by about

70% on a box that relays and buffers incoming email for about 10,000

mailboxes.

mail.* -/var/log/maillog

Syslogging to another machine would be the ideal solution.

For postfix, I also set these in /etc/postfix/main.cf

minimal_backoff_time = 2000s

maximal_backoff_time = 8000s

maximal_queue_lifetime = 2d

message_size_limit = 10240000

qmgr_message_active_limit = 20000

qmgr_message_recipient_limit = 20000

transport_retry_time = 120s

Basically just taming the queue to work not quite so hard to send all the

bounced spam back to the sender.

The last three were doubled. I am not 100% certain I understand the

qmgr_message ones, but my understanding is that it increases the amount of

ram the queue can use. More ram operation == less disk thrashing so that's

my reason for that.