Recover deleted mail using the new Exchange Admin Center in Office 365
In the last quarterly update, we covered the new Exchange Admin Center in Office 365. Exclusive to the new admin center is the ability to recover deleted items back into a user’s mailbox. This process has been available using PowerShell for some time.

Keep in mind you can only recover up to the limit of your single item recovery policy. By default, this is 14 days in Office 365, but can be increased to 30 days (although you will need to set this ahead of time).
You can read more about how to recover deleted items in the following article.
Preventing Reply-All Storms in Exchange Online
Microsoft has added a new feature to combat reply-all storms. These storms are particularly prevalent when numerous people execute a reply-all to a massive distribution list.
Microsoft’s initial reply-all protection will block replies to an email thread for 4 hours if it detects more than ten reply-all messages within 60 minutes to a thread with over 5,000 recipients.
The eleventh sender will receive a non-delivery report titled Reply-All Storm Protection with the reason the message was blocked.
[Read more…] about Exchange Online Updates (June 2020)