If your business email is on a pop3- or imap-server indeed they do (I hadn't seen that), although the link you provided doesn't show how they handle username and password to access the account on the server. But let's assume they do.
But that, of course, for the usual pop3-account only backups the e-mails still present in the inbox on the server. Not the sent items, not anything that was deleted form the server. So with the usual delete-from-the-server settings, there backup hardly does anything.
Be sure to check carefully if all goes well, if you plan to use their services.