Avinash Pawar // Viva:
> Hi,
>
> I also noticed the number of TCP connections by *ss -s *command
Postfix uses one process per TCP connection - one SMTP client
or one SMTP server, depending on the direction.
> Whenever it goes beyond 900 then mail sending speed is 5-6 mails per second.
>
> When the connections are below 900 then the mail sending speed is 100-200.
You need to identify the bottleneck: most likely that is memory or
disk.
When the process don't fit in memory, then the machine will slow
down dramatically as it loads the disk with paging and swapping
I/O. And the disk is the slowest component of the system.
Wietse
