Document recommended email setup

I can help draft a page for this in the Drupal CMS Guide if someone can provide a list of "What we recommend users do when they move to hosting ...". It doesn't have to be polished, just a general here's what we recommended. And I can work on documenting specific steps required to make that happen.

Thanks for picking this up. I think the gist is that we ship with a working setup using PHP but we recommend that users set up SMTP. I should have documented it for myself when I made this issue....