Microsoft will automatically block ‘reply-all-storms’ in Office 365

Microsoft wants to detect faster in Office 365 when organizations find themselves in an ‘Answer All storm’. The company will block such e-mails faster if the program notices that many e-mails are sent in succession.

Microsoft wants to take action against the ‘major impact’ that reply-all-mails can have on large organizations in particular. These are email chains where many recipients are accidentally or deliberately put in the salutation and where many of the recipients click on ‘Reply all’. “A reply-all email storm can disrupt business operations and, in some cases, even slow down other emails in the organization,” Microsoft writes.

Office 365 will therefore detect when a reply-all storm may occur. If this is the case, further emails will not be sent and senders will receive a non-delivery report back. According to Microsoft, such a block will remain active for four hours. System administrators cannot disable or shorten it for the time being. Microsoft is considering that feature.

A block occurs when ten reply-all messages are sent within an hour in an email list with five thousand recipients. Microsoft says it is using telemetry and customer feedback so the criteria can be refined in the future.

Microsoft announced the feature last year. It is now being rolled out for all Office 365 users.