How do I get my old email from another provider into Zohomail?

How do I get my old email from another provider into Zohomail?

Hi,

How do I get my old email from another provider into Zohomail? I switches MX to Zoho, but my older email cannot be moved to Zoho. I tried the imap (private beta), but moving the email via imap account does not work (it should so I think).

So, how to get my old staff into my actual mailbox?

Wish you a nice day,

Frank