Linux desktops very often run sendmail or postfix or exim or dovecot or some such mail server to handle internal system mail.
But, I suspect you're asking about the pro's and con's of standing up a distinct piece of hardware as a server handling mail for a domain you own. I don't see the value in that. Too much work and hassle and staying on top of security issues. In the end, it's the same mail you'd send or get via Gmail or whoever.