The NHS email system experienced system-wide disruptions as an email was mistakenly sent to everybody on the NHS Mail distribution list.

According to NHS Digital, a bug in a supplier’s system meant that an NHS Mail user accidentally set up a distribution list including everyone on the NHS Mail list.

The problem was exarcerbated when many recipients clicked the ‘Reply All’ option.

According to NHS Digital, 840,000 accounts were affected.

hospital-1802680_1920NHS Digital responded by deleting the distribution list as soon as it became aware of the issue.

Users took to Twitter to complain about the emails, with some identifying the initial sender as an employee at NHS South East CSU.

Dan Sloshberg, Cyber Resiliency Expert at Mimecast, said that the incident highlighted the unavoidability of “human or technical error”.

“Today’s growing dependence on email communication means that if email servers go down, there is a huge impact on employee productivity. This NHS email overload highlights that human or technical error is unavoidable and organisations must plan accordingly.

“Organisations need a cyber resilience strategy to ensure productivity is not lost and employees can continue working even when an incident occurs – whether it was caused by external cybercriminals or unintended internal errors.”