A distribution list is a feature of email client programs that allows a user to maintain a list of email addresses and send messages to everyone in their address book all at once.
Email distribution lists can also be known as electronic mailshots, and whilst they may save a lot of time and effort - they can also go horribly wrong.
In November last year, the NHS's secure email system crashed after an IT contractor accidently sent an email to everyone on NHS England's distribution list, thought to be around 1.2 million people.
The problem was made worse by some recipients also hitting the Reply to All button to complain they'd been sent the message in error and by requesting read receipts. As a result, some 186 million emails were sent, clogging up people's inboxes.
A spokesperson for NHSDigital declined to say who was responsible but confirmed that the distribution list had now been removed to prevent any repeat. The email service was used for sharing patient-identifiable and sensitive information.
Top tips for working with email distribution lists:
- Check who's on distribution lists first - before you press Send. Sending emails to all recipients is only efficient if they all need to read what it contains.
- Avoid requesting read receipts when sending emails to a mass audience - unless this is unavoidable. It causes high volumes of traffic on the network and slows everything down.
- Think about the purpose - only share information via distribution lists if there's a genuine 'need to know' and you're absolutely certain that it's relevant to all recipients.
- Prioritise security and confidentiality - the wider you share information, the more likely it is that people will see it who aren't authorised. So, before sending anything via distribution lists, check document classifications first and be clear about who is allowed to see it.
- Write succinctly - if you're writing for a bigger audience, you'll need to do so succinctly, avoiding jargon and colloquialisms so your message is easily understood. Clarity is particularly important in situations where recipients speak English as a second language.
- Regularly clean up distribution lists by purging names - this is essential, especially when using lists to send information outside your company.
- Promptly action all requests to be removed from distribution lists - under GDPR and other data protection laws, individuals are entitled to have their name removed from distribution lists. Comply with any such request promptly to avoid sanctions.