Email marketing is still one of the most consistent options on the web. It's one of the few places in which you have (almost) unfettered access to your audience. Whether you contact people over time through automated sequences, or send a regular newsletter, this avenue is one of the best ways to show up in front of people on a consistent basis.
There are so many ways you can communicate with your audience by email, but most are a mix of the following. If you haven't tried these before, we'd recommend you test them out.