When it comes to digital marketing, there will always be some fancy new technology or platform that all the cool companies are using to hawk their wares. And that's great. We love new things and we love figuring out the best ways to use them. But it's important to put that same amount of energy and investment into mastering the tried-and-true techniques as well. And one of the oldest digital marketing technologies also happens to continue to be one of the most effective: email.