post
https://api.retention.com/api/v1/custom_optouts
This API allows you to upload a file containing email addresses or their MD5 hashes of individuals who you do not wish to be resolved by Retention.com. This is crucial for complying with "do not sell" requests and ensuring data privacy for your customers. You can make up to 5 requests per day, with each request handling 40,000 emails a day.
