It's not like you'd notice the email you're not receiving, so I'm always a little leery of these "it works perfectly for me!" stories for email stuff.

But it's not just postfix or sendmail you need to configure correctly and then put apt-get update/upgrade -y in cron to avoid the damage caused by making a mistake or falling asleep at the wheel. Casual self-hosters have other vectors of attack to mitigate, for example making sure sasl or whatever they may be using for imaps auth is solid, that passwords are strong and routinely changed, that php is also tight and so on. The stakes are relatively high, the efforts to compromise systems for this and other purposes are voluminous and incessant. So I'd say "it takes a village" to do this safely enough, not individual enthusiasts who cannot commit to administering a server diligently.

Any tips for somebody looking to move to my own smtp server? It's been on my mind a few months, and I want to move away from gmail to my own server or to another service, preferably one I pay for.