OutlOutlook This is a good option, because it allows you to clean your account without losing your data. You simply move it to the archive and get it out by request.
But there are some problems with O365 archiving that you should be aware of.
The most obvious problem with Office365 email archiving is that the archived emails are not available offline. If you travel a lot it can be a real headache. Of course you can keep all your archived mailbox locally but what’s the point in going cloud then?
Another big trouble you can encounter is related with storage limitations which I have already mentioned above. If you reach the storage limit your Office 365 mailbox will simply stop receiving new emails. Office 365 administrators can set up archive mailbox quotas so as to limit the email archives with the certain mailbox size or age, but it can cause additional costs for subscribtion. Different plans offer different features. On some of them archive mailbox is limited, on others it is not. Anyway if you reach the limits you will receive an warning message. The default options for Exchange Online are the following: archive quota make up 50 gigabytes and you receive the warning at 45 Gb.
In some cases companies are constantly monitored by government which requires email accessibility by request. And if your archived emails were deleted because you simply did not have enough storage you may get into real trouble.
To prevent this situation you should always have a reserve copy of your mailbox on some side storage. If you regularly backup of your Outlook to the cloud you may save your money and nerves for getting access to your emails.