I'm running my own mailserver on a VPS for about 4 years. I'm using https://mailinabox.email/ It's a one command installer that installs everything you need for a mailserver to run, including roundcube webmail, nextcloud, DNS server, static html page hosting, and it runs on low resources, I'm using a very cheap VPS server with 1 core and 1GB RAM, I pay 3.79 euros monthly for VPS and it's been running great.
I'm running my own mailserver on a VPS for about 4 years. I'm using https://mailinabox.email/ It's a one command installer that installs everything you need for a mailserver to run, including roundcube webmail, nextcloud, DNS server, static html page hosting, and it runs on low resources, I'm using a very cheap VPS server with 1 core and 1GB RAM, I pay 3.79 euros monthly for VPS and it's been running great.