==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.6.4
- Deployed with iRedMail Easy or the downloadable installer?  downloadable installer
- Linux/BSD distribution name and version: Debian 12
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  LDAP
- Web server (Apache or Nginx): apache
- Manage mail accounts with iRedAdmin-Pro?  NO
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I'am looking for some additional settings that can be used for iredmail pack to improve faster email sending. I've already used :

smtp-amavis unix -  -   -   -   4  smtp
and $max_servers = 4;   

I've used these settings  to use max processors but my server is not that overwhelmed it has low cpu usage so can I change something in dovecot or amavis to improve the sending rate.