Targeting the VPS user with the last 2% of Let's Encrypt, Reverse Proxies, Containerization, and "VPS" Sub-domains is the new goal.
I believe poste.io managed to nail the KISS principle.
A new landscape of reverse proxies, let's encrypt, and docker introspection.
Reverse Proxies w/ integrated Let's EncryptAn ACME Shell script: acme.sh Traefik is a modern HTTP reverse proxy acme-companion is a lightweight companion container for nginx-proxy. Caddy is an extensible server platform that uses TLS by default. This plugin enables Caddy to be used as a reverse proxy for Docker containers via labels. This project comes as a pre-built docker image that enables you to easily forward to your websites running at home or otherwise, including free SSL, without having to know too much about Nginx or Letsencrypt.
poste.io is an email server that starts out of the box with Lets Encrypt and a VPS sub-domain, "mail.example.com", (having setup your MX records before hand, etc) in one minute.
I have been trying to install several email servers that all offer "containerized" versions that do not work on my VPS server out of the box like poste.iohttps://github.com/nodemailer/wildduck https://github.com/nodemailer/wildduck-dockerized https://github.com/postalserver/postal https://github.com/modoboa/modoboa https://github.com/docker-mailserver/docker-mailserver https://github.com/Mailu/Mailu https://github.com/dovecot/docker https://hub.docker.com/r/instrumentisto/dovecot/#! https://james.apache.org/ https://www.cyrusimap.org/ https://github.com/haraka/Haraka
The VPS consumer is the last 2% of a product.
As these "Email Servers" projects demonstrate it's the last 2% that makes the difference (Let's Encrypt, Reverse Proxies, Containerization/Docker, and VPS sub-domains)
Some projects like Haraka that are "simple" to setup are more complicated than a product like poste.io that do the same thing.