I know people hate thread bumpers, but for anyone who wants to self host their own mail server you can try mail in a box. Its free and open source easy to setup mail server.once you get it setup then you can just connect your smtp credentials and start sending mail with it. It should run pretty comfortably on a $5 or $10 vps. the advantage is you also get a fully functional email server so you can have staff email addresses and stuff.