Email Automation is automated email sending based on triggers, timing, behavior, segments, or lifecycle stage.
It matters because email is one of the few channels a business can own directly. Strong email fundamentals improve trust, deliverability, segmentation, and long-term lead nurturing.
Example
Someone requests a buying guide and receives the promised download automatically. A later message is sent only if the contact remains eligible for marketing, and a purchase can move them out of the prospect sequence.