That means no "marking-as-read," "just peeking," or "catching up." Public servants who've been told to stay home may even be asked to hand over their mobile devices — just to make sure.
Federal employees who do check their inboxes will technically be breaking an obscure law known as the Antideficiency Act, which was passed over a hundred years ago and carries a penalty of fines or even imprisonment.
If there isn't time to notify an employee whether they'll be affected by the shutdown before it hits, the government can't use work e-mail to tell them about it:
The same rules hold for telling employees when they can come back to the office. Excuse me while I go fantasize about a fleet of federal carrier pigeons.