How do you politely inform people that you will not be checking your email every second of the day or after a given time in the evening?

Megan U.
One idea that some people use is to articulate your e-mail policy in the automatic signature at the bottom of each e-mail (e.g. "I observe e-mail free evenings and weekends. I strive to reply to all e-mails within a 24-hour window on weekdays" or whatever makes sense for you).