Microsoft Tackles 'Reply All' Misery

John Lister's picture

Microsoft wants to stop one of the most annoying parts of email. It's going to try cutting the vicious cycle of the "reply all" message storm.

The problem arises when somebody sends a group message to a large number of people and then one of the recipients mistakenly (or perhaps worse, deliberately) clicks on "Reply All" rather than simply using "Reply" to address the original sender.

Not only does that mean the entire group seeing the reply, but it can quickly spark others to reply, extend a conversation, point out the error, or make a joke. In some cases, the configuration means that all of these replies also end up going to everybody on the original list.

Microsoft Suffered Own Storm

That can be an amusing diversion for office workers, but the numbers can soon add up and clog up email servers, particularly if and when somebody attaches a file such as an "amusing" image.

Even Microsoft experienced the problem itself earlier this year when what was meant to be a note offering discounts on software for staff quickly turned into a chain of messages, each going to 52,000 people. It only took a tiny proportion of that group to reply to any message to prolong the agony, and make it difficult for users to send important emails or indeed to spot them in inboxes.

15 Million Messages An Hour

Indeed, Gizmodo recalled a similar incident way back in 1997 when a "reply all" chain created 15 million emails in just one hour. (Source:

Microsoft is now adding a "Storm Protection" feature to Microsoft 365, the online version of the Office software suite. The initial setting will mean the feature triggers if there's a chain of 10 "reply all" messages going to more than 5,000 people within a one-hour period.

If that threshold is met, the email conversation is effectively put on hold for four hours. Anyone who does try to reply will get an explanation and a suggestion that if they do want to reply, they specifically address it to either an individual or a small number of named recipients. (Source:

The threshold will be tweaked depending on how it works in practice. Microsoft is also considering letting system administrators choose their own settings.

What's Your Opinion?

Have you ever experienced a "Reply All" storm? Is Microsoft smart to add such a feature? Would it be better to educate users to take care when replying?

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ferretsgold's picture

It's about time Microsoft did something about this. Unfortunately, it is too little. If someone hits the Reply All, Microsoft should present them with the question of whether this is really what they meant to do.

jamies's picture

Maybe phrase the question along the lines of asking the selector if they are willing to receive n,nnn,nnn (whatever the number of intended recipients is) acknowledgements of receipt and maybe another n,nnn,nnn reply messages.

Also interesting that in 1997 with the vastly more costly storage and slower linespeeds, 15 million messages in an hour did NOT get the response from Microsoft that what is in relation probably a minor inconvenience to themselves gets some action to 'address' the possibility.

Greg1956's picture


our company experienced this in the early 2000s when one of my staff and her best friend went on holidays at the same time.

Both sent farewell messages as they went out the door on Friday night.

Monday morning the Email server has crashed and it is full of their autoreplies.

It took several days to clean up the mess and track down the culprits and disable their email for the duration of their holidays.

What a good idea to fix this problem.