I thought Exchange Online Archiving was like a separate mailbox (maybe like a shared mailbox) and that I had to choose by myself the emails/items one by one, which I wanted to be saved there instead of the primary mailbox. Mostly I use the Desktop outlook software and I don't care for the Web Interface.
When I realised that is not working like this, I create a support ticket to Microsft and I started asking my questions & worries. With the lady from IT support we concluded let's forget Exchange Online Archiving and just create a second normal mailbox. So we stop the phone call and disable the Archiving feature in order to create a second mailbox. When I did that in the web interface, I notice that "My Archiving" place is still there and, most important, a part of the structure of the main mailbox was already copied, and some of 2020 or older was moved under the Archiving from the mailbox, but it was to later because I already disable the feature. After a while, the "My Archiving" place disappeared.
If I re-enable the "Archiving" solution, will I be able to find these "old emails"? How can I recover these emails? Is possible for Microsoft to provide me 3-4 days snapshot of my mailbox?
PS: I never change the retention policy settings. 
