There is an assumption that Office 365 (O365) is backed up on your behalf. If you follow this assumption there could be repercussions down the line. Whilst there is a recycle bin that will allow you to recover deleted documents for a 30 day period, the problem is that in the case of accidental deletion you may not notice in the first 30 days then which it is too late.
Whilst Microsoft are responsible for maintaining their services and infrastructure, it is your responsibility to protect your data.
In fact the Microsoft Services Agreement states “We strive to keep the services up and running; however, all online services suffer occasional disruptions and outages, and Microsoft is not liable for any disruption or loss you may suffer as a result. In the event of an outage, you may not be able to retrieve your content or data that you’ve stored. We recommend that you regularly backup your content and data that you store on the services or store using third-party apps and services.”
The easiest way to back up O365 in my opinion is to use a 3rd party solution. These can be used to backup individual emails, mailboxes, SharePoint sites and OneDrive for Business files meaning they can all be recovered within seconds and are restored to the exact same location.
These products can be easily setup and are straightforward to manage. The cost of doing this is usually quite low and is on a per user per month basis with retention periods of around 12months.
Disclaimer
The information was correct at time of publishing but may now be out of date.
