Change courier to dovecot

Hi,

I receive this notification at morning.

Code:

The cPanel & WHM update cannot proceed because the following service has been deprecated: Courier

You have 29 day(s) and 0 hour(s) until we remove Courier and replace it with Dovecot.

To continue using Courier, you must change your Update Preferences in WHM to Long Term Support (LTS). By switching to LTS, you will not receive new features and eventually will stop receiving security updates.

cPanel & WHM version 11.52 will be the last LTS version to support Courier.

For more information about Long Term Support: https://go.cpanel.net/longtermsupport

I try to change but from WHM in my server there are no menu for mail server configuration. How to do manually using CLi?

Thanks.