When and how can I use In-Place Archive?
When do I have In-Place Archive?
In-place Archive is a feature available in most of all Office 365 (with Exchange Online) subscriptions .
What is the Archive quota?
Default the storage quota is in the archive mailbox is:
Exchange Online Plan 1: 50 GB
Exchange Online Plan 2: 100 GB
Unlimited storage is a premium feature that requires one of these subscriptions:
Exchange Online Plan 2
Exchange Online Archiving
Both start with a default 100GB Archive mailbox, but when auto-expanding archiving is enabled it's 'unlimited'.
More information / Microsoft articles:
To access their archive mailbox using Outlook, users needs an licensed Outlook 2013 or higher.
Sometimes an Outlook 2010 is also possible, detailed information can be found in this Microsoft Article.
How do I enable In-Place Archive for one user?
Go to the Exchange Admin Center
Recipients -> Mailbox
Select a mailbox and then you can enable Archiving:
Then the mailbox type is change to type 'User (Archive)'
It's possible you see this error below for a couple of hours. You can continue.
After a while (minutes or hours) the 'Online Archive' will be automatic pushed to the Outlook client as additional mailbox: