Migration of hosting accounts to a different server

I currently have around 13 cPanel accounts on a VPS from Liquidweb. I recently purchased a Contabo server and have AlmaLinux 9 running on it together with HestiaCP.

All 13 accounts are essentially WordPress sites. 4 or so of the accounts have a large amount of email which needs to be moved over. I understand that moving mail from a cPanel account to a HestiaCP while is not difficult and can be done it isn't a point and click exercise. So if you have understood what I have been talking about thus far please do reply.

The main reason for moving is cost reason and once successfully migrated will likely need someone on-hand for other work.