It is entirely possible to host your own email server, I do it for example, there is no way to reliably know that other people are receiving your message.
That is: When self-hosting email you can reliably receive email, but can't reliably send it.
The fundamental problem is that email is a broken protocol and too many people are making too much money mitigating the problem of spam rather than solving it.
Companies that need to keep their email servers working have to deal with extortion from anti-spam companies to attain reliable message delivery. It is a racket.
This means that even if you get everything working 100% with all the perfect security protocols and conventions in place the chances of anybody actually receiving your email at this point is roughly 50/50. There is nothing you can do to ensure reliable message delivery without getting your servers whitelisted by most of the popular spam houses. And even then you have to deal with large public companies like Google and Microsoft that may or may not forward messages to recipient based on secret rules that change constantly.
So while it is possible, I host my own email, I can't rely on it. I use gmail for situations were reliability matters.
It is better to use something like Mastodon for correspondence if you can help it.
That is: When self-hosting email you can reliably receive email, but can't reliably send it.
The fundamental problem is that email is a broken protocol and too many people are making too much money mitigating the problem of spam rather than solving it.
Companies that need to keep their email servers working have to deal with extortion from anti-spam companies to attain reliable message delivery. It is a racket.
This means that even if you get everything working 100% with all the perfect security protocols and conventions in place the chances of anybody actually receiving your email at this point is roughly 50/50. There is nothing you can do to ensure reliable message delivery without getting your servers whitelisted by most of the popular spam houses. And even then you have to deal with large public companies like Google and Microsoft that may or may not forward messages to recipient based on secret rules that change constantly.
So while it is possible, I host my own email, I can't rely on it. I use gmail for situations were reliability matters.
It is better to use something like Mastodon for correspondence if you can help it.