Panic Spam
When an individual is desperate for information or an answer to a question to the point where he or she will send an email to everyone in their address book (or in the case of the enterprise organization - multiple distribution lists) leveraging all of the urgent features of the email program including starting the subject line with an exclamation mark (!)
When someone is in the field, and really under pressure they are going to send an email to every distribution list they can find, and it does not matter how many times you say this DL is for X,Y or Z. They will still do it. The problem is - Panic spam is not productive and having a single email for all technical discussions is great for a company with under 50 employees. Some of us already get a lot of email and like to leverage rules to optimize our inboxes and prioritize discussion.