Somebody emailed the whole company and now everyone is replying all to be taken off the list

Forty-one new messages since lunch. Gary has now asked us to stop emailing Gary four times. — Employee at a big firm, 2009

On November 14, 2016, one email reached about 840,000 NHSmail accounts in England. Some people hit reply-all to ask to be taken off, which sent the request to everyone on it. NHS Digital's report counted about 500 million emails in about an hour. Some work email systems now cut that off: once a big thread piles up enough replies, they block more for hours. Good. But that's your employer's setting, not yours. Half a billion emails, and many of them said stop.

For now: don't reply-all to ask off a list; and when you write to a big group, put the addresses in Bcc.

The full file

One big software company did the same thing to itself in 1997. Somebody on a list called Bedlam DL3 hit reply-all to ask off. About 13,000 people were on it, roughly a quarter of the company, and others joined in, some begging everybody to quit replying all. About 15 million messages went out in an hour, and the cleanup took two days.

The person who sent it was cleared of blame. NHS Digital said a bug in a supplier's system made the list far bigger than it should have been, and one report says the sender thought it was going to fewer than 20 people. Some staff counted over 300 reply-alls in their inboxes, and a day later a few still couldn't open them.

The 2020 fix is a counter. When a thread with more than 5,000 recipients gets more than 10 reply-alls in an hour, the system blocks further replies for several hours and sends the sender a bounce. Twenty-three years after Bedlam. Took them long enough.