You can fetch mail from your PLESK server and have it imported into cPanel.
- Simply login to your cPanel
- Access your webmail and access Horde
- Once logged in, on the left hand side, click OPTIONS then Mail
- On the center of the screen under “Message Options” click “Fetch Mail”
- Create a new account, enter your details from your email account located on your PLESK server (for the incoming/outgoing servers, use your PLESK server hostname)
- Email will then begin to be downloaded into your cPanel inbox.
For data, you can make a tar file of website on your plesk server, mysql in .sql format and webfiles in tar and then you can copy that on cpanel server account and restore it.