email delivery
Currently no built in way to deliver email from the server as Postfix (etc) not installed for security reasons and to keep your server IP address from ever getting blacklisted by Spamhaus etc.
The best way to send email from WordPress is signing up for an account at SendGrid, Mailgun etc then using an API plugin for WordPress to send those emails.
As far as server level emails like error log alerts and things like that, we are considering adding support for email APIs too. If you have feedback on any of this please let us know.