BenchmarkONE employs throttling with certain email sends. The smart throttling will only be necessary if you have many of the same email domain within the list, like "Gmail.com".
On a per outgoing IP basis, our senders will adjust their mail flow depending on its current standing with email inbox providers.
If you require specifics, you can provide BenchmarkONE support additional details such as the number of contacts on your email list, the most common domains (gmail, outlook, etc) and the number of emails within those domains. We can then provide specifics for best practices and suggestions for maximum inbox deliverability.