What is the Office 365 Online Email Archive?
The Office 365 Online Email Archive is basically another mailbox inside of your email account that completely mimics your current folder structure. All mail older than 2 calendar years will automatically be moved into the online archive.
Why do I need an Online Archive?
The Online Archive provides a way to keep your regular mailbox working smoothly and efficiently. By moving all mail older than 2 years out of your inbox and into another location, your daily mailbox will much faster and more efficient.
Why is it an "Online Archive"?
The reason it is called an "Online Archive" is because the archive folder and all of its sub-folders are not synced to your computer automatically. Messages are visible if you browse through the folders or if you search the archive however those messages won't regularly sit on your computer, taking up even more space.
How do I access the messages in the Online Archive?
Your Online Archive appears as a separate item inside of your mailbox. Sometimes, if you have a lot of folders, it may be hard to spot. The Online Archive appears at the bottom of the left-hand folder view, underneath all of your folders. If you've ever opened a shared mailbox, it will appear in a location very similar to those. Take a look at the screenshot below for an idea on your Online Archive's location.
When I search of an email, will my archive also be searched?
Unfortunately, if you search your mailbox, the Online Archive will not be searched at the same time. This is due to the archive actually being separate from your normal mailbox.
The Online Archive is searchable, however. Simply click on the Online Archive folder and enter your search items in the search box. A menu of choices may appear (depending on your email client) giving you additional filtering options if you desire.
Do I have to use the Online Archive?
Every mailbox will be configured to use the Online Archive as this is the default behavior of Office 365 provided by Microsoft.