If you have cold data we recommend sending slowly to the database so we can monitor how the data is performing. For example, if the platform detected a high amount of bounces we can try and slow this down (or stop) before the bounces impact your IP. Once the IP is infected, this generally means our emails end up in the junk box.
If you know it's customer data and know it will perform well, throttling isn't needed as much and you can send this all in one go.
Contact your account manager if you need any assistance with throttling rates.
