Why is postfix version obsolete?

This old version is experiencing some errors.

mail_version = 2.10.1
milter_macro_v = $ mail_name $ mail_version

I want to update it myself. But I am afraid of problems in integration.
New Version: http://www.postfix.org/announcements/postfix-3.4.6.html
If we can update, how will it be done.
A total of 30 e-mail addresses of our existing customers are used.
How to update without problems.

@CyberPanel ?

Because Centos default repository comes with that version.

Can’t update?

I am not sure , but quick google indicates that is a lot of changes in configuration and files , so it might break something.

by the way , I believe Plesk , cPanel and among others , are using this very same version as well.

on centos , version is always old , but stable.