Any good enhanced newsletter extensions?

Any good extensions for Opencart 3.0x to update the built in newsletter system.

I would like something that has templates, and lets you design your own templates.
That also lets you easily add products from your store.
And handles sending the emails (in small batches if needed)
Some type of automation or subscriber list integration would be great too.

Or, are most people using some third party service like Mail Chimp or Constant Contact and integrating that with OpenCart using the appropriate extension.

I've used the Mailchimp Integration extension in the past. IMO it's the best extension you can get for newsletters. It's well worth the money in my view:

https://www.opencart.com/index.php?rout ... on_id=1707

Top of my wish list is to have it ported over to the Mautic email marketing system. That would be a dream.