Move email without backup restore

anyone here know how to manage this ?

server A (new version of cyber panel)
email hosting

Server B (version 2.1.x)

i want to move account from server A but only the email …
so i will do that manually without backup restore (since i have trouble with those feature and they are different version)

how and what i must do…

https://imapsync.lamiral.info/X/

i dont have the cred… it’s my client’s account…