Over the last few years I've used almost all the paid platforms, like Mailchimp and Constant Contact etc, and most of the free ones, like Sendy, Mautic, etc - this platform is the best. No list size or subscriber limits, no extra costs for advanced features!

There are improvements to be made, and they have a roadmap, but it's already an amazing platform, ready for production use, and can do quite a lot right out of the box. There is an API for customizing it even further if you're a developer like me.

It supports any authenticated SMTP connection you want to send out from, but it's better to use one of their ESP API connections such as Mailgun, Amazon SES, Sparkpost, or Easylink, because then you get real-time delivery and bounce rate feedback via the APIs.

It supports building your own signup forms and pop-ups, your own campaigns (broadcasts) and drip campaigns (funnels).

Depending on the Appsumo plan tier you buy, you can have multiple white-label brands that you sell or provide service under (they call this a frontend), each with your own logo and custom colors via their new Custom CSS area, or white-label your service for others. Each frontend brand supports an unlimited number of "client brand" accounts, and unlimited number of client user logins under each account.

The backend UI is nicely organized and pretty simple to figure out, and there's plenty of documentation and a nice FAQ as well.

The campaign (they call it broadcast) editor comes with a ton of predesigned templates you can use as a starting point and just edit, and the Pixabay integration is super nice, I love it. The editor in Sendy is horrific and near-worthless, so I've had to use Stripo.email and import them in, but no more, this editor is almost as nice as Stripo, and just works.

The drip campaigns (they call this a funnel) have a ton of features and flexibility, and advanced logic is built-in, with superb tag integration.

Touching on the technical server details... It uses a dozen or so separate Docker containers to run all the web services, and includes command-line scripts to download them all and run or restart them all, so don't try running this on a shared control panel, as it will conflict and interfere with their web server etc, it is pretty much self-contained. I had an empty RackNerd VPS sitting around, so I just used that, and a few minutes later it was installed and running. They do have a nice deal from RackNerd available for a basic VPS that runs around $32/year or so, def use that if you don't have a favorite VPS provider (I also recommend Vultr, Hetzner, Slicie). It doesn't require a ton of technical skills, but basic SSH experience is helpful, and their support is super responsive and willing to help or answer questions.

All in all, I am very happy with the purchase, and loving all the features and functionality that is built-in and working out of the box, and looking forward to the roadmap features being added.