Mail server and client for domain, where to start?

Question

Mail server

There is a site like domain.com.
The site runs in the cloud with Ubuntu installed.
It is necessary:
​​1) Create a web server so that everyone can register and receive mail like [email protected]
2) After registration, it is necessary that the user has access to the web interface where he can check the mail and store it.

Are there ready-made management systems for working with email's?
If not, where to "dig" in order to create it manually starting from the web interface, backend, mail server, etc.?

Answer 1

where to begin?

In my opinion, it's worth starting with a detailed thought on the question of how you will send mail.
When using even a "clean" single IP of your server, there is a very high probability that services like Gmail will send letters from you to spam by default, or even silently drop. And this despite the fact that Gmail is not yet the most "finicky" in this regard.
In a good way, you will need a network of IP addresses (relays), which you will first gradually “warm up”, accumulating a reputation, and then monitor that reputation very carefully .
If the service you want to create will be free, I can hardly imagine how it can be done. Public availability will further complicate the task.

Answer 2

Thousands of them. But for some reason, everyone sits on gmyle and mail.ru. Well Yandex and rambler isshsho.

Answer 3

If on topic, then here: https://mailcow.email