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.
A question asks how to remove a bunch of emails from a shared mailbox. You can use OWA to do the job, especially with its Cleanup Mailbox option, but perhaps some administrative action is needed.
A new Exchange feature rolling out inside Office 365 allows meeting organizers to block people forwarding their meetings to all and sundry. The latest versions of OWA and Outlook 2016 click to run support the UI for the feature and blocks are built into Exchange Online and Exchange on-premises servers to stop blocked meetings sneaking through.
Like all mail-enabled objects, Office 365 Groups can have multiple proxy addresses. Microsoft has fixed a bug in the Set-UnifiedGroup cmdlet so that you can remove proxy addresses from groups, but take care before you do.
The Search-Mailbox cmdlet is very powerful when it comes to removing items from Exchange Online mailboxes, but it can’t deal with other Office 365 content.