AWS is going to begin charging extra for routable IPv4 addresses soon.
There's really no point in having a relay in the cloud anymore anyway,
since a) all outbound messages are sent via the local relay and b) no
messages are sent to anyone except me.
The *postfix* role installs and configures the Postfix MTA. It currently
supports a number of modes, including direct transfer and relay. Relay
mode supports STARTTLS security and PLAIN authentication.
