My media set was set to "not appendable", but I want my medias to now be appendable (the ones already used). How can I change them to be appendable ? I changed the media set to appendable, but that didn't change the medias themselves. Thanks a lot.
Why don't you try creating 2 other brand new mailboxes, and redirect the restore towards those 2 new mailboxes, then, with Outlook, you could transfer the messages from the newly created mailboxes to the original ones.