curl --request DELETE \
  --url https://api.sendpost.io/api/v1/subaccount/suppression \
  --header 'Content-Type: application/json' \
  --header 'X-SubAccount-ApiKey: <api-key>' \
  --data '{
  "suppressions": [
    {
      "email": "gilfoyle@piedpiper.com"
    }
  ]
}'

{
  "message": "Suppressions have been deleted successfully"
}