This is my main email newsletter software

I really like using MailPoet, I have managed to save myself and several clients big fees they were paying on other platforms.

All the usual features are there including registration management / confirmation.
List management, segmentation.
Email templates and design editor.

One big advantage for WordPress users:
Why send newsletters outside of your platform when you can use MailPoet which has access to your existing media library for logos and images?
This really helps you to stay on brand.

And many new features appearing regularly and users can submit to their roadmap.