For cases in which users need to whitelist IPs for our email server, we need to configure the email server to use Mandrill's static server, instead of the default dynamic one.
This will be available via our server side configuration file:
To switch to the static email provider, replace the existing "api_root" configuration to "http://static.mandrillapp.com/api/1.0" (which you can see one line below the existing "api_root").
Mandrill's static api can use any of the IP's listed below, so make sure to whitelist all of them in the firewall:
And of course don't forget to whitelist the domain itself: static.mandrill.com
*Please note that Mandrill IPs may change from time to time.