> Used it because I didn't really care about the account and expected some shitty roundcube thing, but have been blown away.

For what it's worth, I self host a few e-mail servers and modern Roundcube is actually a pleasant experience, even if I like connecting Thunderbird directly.

Here's the mail server I like: https://github.com/docker-mailserver/docker-mailserver

I still very much rely on some cloud vendor e-mails for uptime and deliverability, though. Otherwise, with random VPSes you risk the IPs having bad reputation or having a plethora of issues (such as some providers not allowing e-mail ports).