If you have to handle emails on vacation, then it’s not a vacation. It’s super important to unplug every now and then, turn off your computer / cell phone and take a break from email. The best indication that you’ve built a solid business is how long it can operate WITHOUT you. Every entrepreneur’s goal should be to build a company that can run without them forever. If your business is not at this point, then you don’t actually have a business, you have a job and you are the bottleneck.