Answered by Stephanie, Hiring Expert at AT&T Inc., on Tuesday, May 23, 2017
HI there! This is not a one size fits all question. The answer depends on your job, the immediacy of the question/response and other factors that would impact the decision to respond.
If you are working in a position that is on a 24 cycle, there is no time that is off limits for sending email. If you are an hourly employee who is off the clock, you shouldn't be working. Pretty straight forward.
If this is an emergency, by all means respond.
And the last thing I'd like you to think about is talking to your supervisor. What are the expectations? I would never hesitate to send an email over the weekend, at night, when I have a question, when I have an answer. Why? Because I have dialoged with my boss about the expectations of my position, their expectations of my response time and how the flow of work is going to be the most successful. This is not to say that I'm expected to work 24 hours a day. This is all about open communication and a true understanding of priorities.
Open the channels of communication!