Configuration for outbound IP address

Background

Generally lots of hosts that use CPANEL or WHM etc. have 2 IP addresses. PHP CURL uses the first known IP, and this feature allows developers to specify the IP addressed used to communicate with Akamai.

Users that have dedicated IPs, but still are being blocked by Akamai, will need to add a constant to the wp-config.php file:

define('MAILCHIMP_USE_OUTBOUND_IP', 'the.ip.address')

When the IP is defined, the plugin will bind that outbound IP to the api requests.