You *can* set up your own email server. There isn't anything to "fix" (unless yo...

You can set up your own email server. There isn't anything to "fix" (unless you can "fix" all the spammers) but does require setting up SPF in your DNS and it helps to support DKIM/DMARC. Also, your internet provider / VPN host likely blocks port 25; if that is the case, you need to use a "smart host" email relay service.