To migrate your emails and mailboxes to 20i, you can use our in-house Email Migrations tool. This will let you migrate your IMAP mailboxes, your Gmail mailboxes and your Outlook mailboxes into 20i.
To do this:
If you the sync fails to start, this is likely due to the credentials not being correct. You should confirm that the password you have used is correct and that the hostname is also correct.