“Reply-All email storms”, hasn’t anything to do with the weather. The email storm or reply allpocalypse, as it’s also known, is when there’s a large- number of recipients in a reply-all mass-mailed email, such as a company- wide notification.  If multiple employees happen to hit the Reply-All button, at the same time the storms effects, result in crashed email servers or a slow- down of email traffic.

 Reply-All email storms in Office 365

Even Microsoft has had to face their own reply-all email storms. The first in January 2019 and then again in March 2020, resulting in more than 52,000 employees contributing to the slow-down of the company’s internal communications for hours.

At some time or another a company’s email servers are going to crash due to their employees participating in a reply-all storm either unintentionally or mischievously. During the Microsoft Ignite conference held last year Microsoft announced its commitment to help prevent these storms on Office 365 Exchange email servers to prevent this issue.

And, this week they have come through with their promise to combat the traffic slow-downs and crashes.  Microsoft have rolled out this new feature for their Office 365 customers worldwide. The new “Reply All Storm Protection” feature will block all email threads with more than 5,000 recipients, that have generated more than 10 Reply-All sequences within the last 60 minutes. The new feature, now triggered, will block all replies via Exchange Online for the next 4 hours. In turn this frees up the server by shutting down the reply-all storm, to focus on actual emails.

Microsoft have stated they’ll continue to improve the “Reply All Storm Protection” feature

Firstly, by promising to add controls for exchange admins in order to set your own detection limits.

Secondly, by storm reports and real-time notifications to monitor potential traffic slowdowns or crashes.

In addition, Microsoft are the testing ground for the feature, having experienced first-hand the reply-all storms. This ensures consumers get the best possible solutions to weather the storm, with up to date protection. The first version has already been successful, says the Exchange team in reducing the storms impact, within Microsoft itself.

The protective feature, no matter the cause of the reply-all storm is beneficial in helping business, stop storm damage.