Summary Microsoft enables a feature to block 'reply-all' email storms
(Web Desk) - Microsoft is rolling out a new reply-all protection feature for Office 365 and Exchange Online. It’s designed to prevent email storms (reply allpocalypse), when hundreds or thousands of people start replying to an email thread after someone forgot to BCC everyone or a distribution list was misconfigured.
Initially the Reply All Storm Protection feature will mostly benefit large organizations that have large distribution lists. When the feature detects a likely reply all storm taking place on a large DL it will block subsequent attempts to reply all to the thread and will return an NDR to the sender. The reply all block will remain in place for several hours.
The new block feature will mostly benefit large organizations, and is initially being rolled out to detect 10 reply-all emails to over 5,000 recipients within 60 minutes. It will then block subsequent replies to the thread for 4 hours.
The reply all storm NDR will look something like this:
Official statement by Microsoft read, “Over time, as we gather usage telemetry and customer feedback, we expect to tweak, fine-tune, and enhance the Reply All Storm Protection feature to make it even more valuable to a broader range of Office 365 customers.”
