Email is like any good business strategy: Don't overdo it
Emails need to be simple and clear in their message. Please, no corporate-speak. They need to speak to the employees, not at them. Employees’ time is valuable, and they don’t want to spend it reading a long, wordy email and then trying to figure out what it said. Simply get in there, concisely tell them what they need to know, link them to more information or a document, and get out. That also minimizes the amount of scrolling the employee has to do while giving them the information they need.