So work this morning has been fun, we got an email from some about a change in their company and they CCd about 360 people in so you could see the emails (GDPR and all that) and then a help desk on one of the recipients picked it up, sent out an auto response to everyone, then another auto response from someone else went out and you can see where it went from there... About 100 emails later they sent out an email asking people to not reply to the previous email and are working with the companies to get the auto responders turned off

Life lesson today: check your emails before sending them!