Exchange Page Patching and Native Data Protection in Office 365

Some backup vendors think that corruption can lead to data loss within Office 365. The possibility exists, but the page patching mechanism for databases incorporated into Exchange Online DAGs makes corruption a lot less likely, especially when mailboxes are protected by four database copies and Exchange applies many other techniques to ensure the consistency of the databases.

https://office365itpros.com/2019/02/07/exchange-page-patching-native-data-protection/