Reply-all storms can disrupt a workday or throttle a businesses’ email system. They’re also exceptionally annoying, which is why Microsoft is introducing a Reply-All Storm Protection feature to its Office 365 and Exchange Online email services.
The new Reply-All Storm Protection feature will mostly benefit large businesses or organizations with large distribution lists. According to Microsoft, the Protection feature activates after detecting 10 reply-alls to over 5,000 recipients within 60 minutes. Once these conditions are met, subsequent replies to the reply-all thread will be blocked for 4 hours. Anyone attempting to reply will run into a non-delivery receipt explaining the situation.
Small businesses may not see a benefit from the new Protection feature, as it isn’t configurable. If you don’t have 5,000 addresses within your distribution list, then the protection feature will never kick in. But over time, Microsoft plans to “tweak, fine-tune, and enhance” the feature to make it more useful to a broader range of Office 365 customers.
According to Greg Taylor of the Exchange team, Reply-All Protection is enabled for all customers now, and does not need to be tested or set up. The new feature has been in the works since 2019, and is already reducing the impact of reply-all storms within the Microsoft corporation, which is famously vulnerable to reply-all storms.
Source: Microsoft via The Verge