I am self employed and have always checked email on weekends and evenings.
How is checking email more stressful than, say, a farmer who must feed stock daily or examine irrigation systems? Or in more primitive hunter/gatherer days when folks always looked for game tracks or kept their eyes open for roots or berries to harvest?
When did sociologists determine that mankind should live in compartments separating work life from home life or leisure?
Probably around the time electricity was invented, and most people no longer worked in an outdoor environment where you pretty much had to work only when the sun was up.
Then the industrial revolution came along, and this meant that most people (by definition) would travel to work outside the home in a place of employment using heavy machinery that couldn't be brought home with them. This was a "compartmentalized" life by definition, I think.
Now we live in a post-industrial age where the typical work place doesn't look much different than a home in a lot of ways ... so we're losing that compartmentalization.
Now that is an excellent point. I have relatives in the Deep South who still farm and they have never had a vacation of any sort because it is just not possible to leave their farm for any period of time. The animals constantly need feeding and tending.