When people see your name attached to a message, it should matter to them and not be a waste of their time. Lag Time One of the biggest faux pas in e-communications is letting too much time elapse before responding to a message. It's rude to wait any longer than one day to respond to a message. In all cases, at the end of every business day, you should attempt to contact everyone who e-mailed you during the day. Even if you can't answer their questions or get into specifics, send a quick note back letting them know you got their message and will get on it the next day.
Different industries tend to play by different rules when it comes to acceptable response times.
In retail, a customer should hear from you in response to their e-mail within a few hours. If individual, personal responses seem too overwhelming, another alternative is to set up an auto reply feature. It lets the sender know that you got their message and will be responding. If you'll be away on vacation or will be out of the office for several days, auto reply serves a different purpose. It Increasingly, e-mail is replacing other forms of communication in the workplace.