Yeah, the IT folks in charge of that are doing so at gunpoint. Had someone do that at a giant size corp and the chain of events goes like this.
Email to all gets sent
A few people wonder why they are getting messages not related to their role and reply all to be taken off a list.
Those reply-all get replicated to the same few hundred thousand boxes causing stress on the system.
You well meaning college sends out a reminder via reply-all that you shouldn't reply-all.
Because those few transactions created somewhere in the order of 2-3 million emails in a short time the servers have a backed up que to chew through causing some people to get things out of order, so maybe they get a 'take me off the list' after the fist 'stop replying all', now this person decides to help reinforce the 'stop replying all' with their own message of the same.
Rinse and repeat until the servers are entirely unable to operate and you need to find a way to flush the cache.
BONUS: Because this is the federal government you can bet that several entities they have contracts with would have automatic relays to distribute incoming messages to required teams for quick responses, so there's a good chance the effect bleeds into private businesses too because Donnie & Musky will demand that ALL means everyone in the federal contacts list.
