I'm currently experimenting with working with Outlook.com for an email server, and have MX records set up to point there and the like. How can I configure systems like postfix to use external servers for mail? When I try to use functions like PHP's
mail() for example, the server logs return this line, obviously because
user isn't a user on my system, but rather is on an external mail server.
ABBAB100B92: to=<email@example.com>, relay=local, delay=0.06, delays=0.04/0.01/0/0.01, dsn=5.1.1, status=bounced (unknown user: "user")
Might it be easier to run a mail server right off of the VPS I'm hosting my website on, so that everything stays local? Or is that not a very good idea?
System is an Ubuntu 12.04.3 LTS