No matter how old it gets, email marketing will still be relevant. Why? Because it is permission marketing. Your target audience willingly gives out his email to you to enter his ‘personal undistracted’ space.
After Search, it has been the most powerful marketing channel with an ROI of 43x to boast in comparison to all other channels combined.
So what you now have is a customer, his personal space and undivided attention, and permission to push your product. What you now need to do is pay due respect to that permission.