I recently had this idea about email servers. In addition to configuring my IMAP clients to normally fetch mail manually or more infrequently, I set up one mail server that “closes” from 7 p.m. till 7 a.m. my time.<p>During that time, it returns a temporary error `450 4.3.2 We're sorry! The mail room is closed from 7 p.m. till 7 a.m. [Time Zone]. Email servers automatically retry, so your mail should be delivered in a few hours.` Depending on their mail provider and the time of evening, some will never see an error, while others will eventually receive the standard “Delayed Mail: no need to retry” message in their own inboxes.<p>I see it as accomplishing three things: first, it tests email servers to see if they properly handle temporary delivery errors by retrying; second, it prevents me from checking my email after hours, or rather, leaves me overnight with only the email I got during the day, perhaps encouraging better habits; and third, it could provide an opportunity for others to consider assumptions about always-on digital services.