Hi, New on the forum and just joined the slack today.. I'm from France and currently working as a freelance developer web / mobile. I can suggest for the website to add a newsletter field (highlighted) I guess you already have an emails DB but I think it's really missing on the homepage
I think our own service, on our servers. But, if you can suggest any good external e-mail / newsletter managing service, or good software (PHP preferably) it would be nice.
I personally use Mailjet, for newsletter and transactional emails, it depends on the volume, it can be expensive, But for newsletter it can be really easy to design custom template like this (image attached). It looks really more professional !