During the restore of a message to a mailbox from the web search, when you attempt to open the list of mailbox folders, you receive an error message:
An error occurred while retrieving the list of mailbox folders
Give the SourceOne Account the correct permissions on those mailboxes/stores that you are trying to restore to.
First, check the mailbox you are trying to restore to, does not have a limited quota. If the quota is exceeded, you will not be able to restore to that mailbox.
Refer to the SourceOne Installation guide that provides examples of the Powershell commands needed depending of the MS Exchange server version used.