To keep things simple, All you need to do is the pass the pool name containing your IP as the value of the 'ippool' parameter in your API/SMTP calls.

However, if you wish to have more advanced control over your IP assignment & usage, Please refer the preference hierarchy to understand how you can use your IP more flexibly.

We determine which IP needs to be used based on the preference hierarchy stated below

  1. The value passed in 'ippool' parameter.
  2. The IP assigned to the Sending Domain.
  3. The default IP of the account.
    Please refer to the image below to understand the algorithm.