Introduction
Engaging with other people can be confusing, even at the best of times where communication is largely through text, and can easily be misunderstood. So what etiquette should you use in email to make the recipient feel comfortable, and to make sure you look professional?
In this context, the main purpose of etiquette is to show consideration for others. It provides anchor points to prove you're on the same page, and at least have some mutual understanding. In other words, etiquette is a subtle way of building rapport.