Email throttling refers to the practice of controlling the rate at which emails are sent to avoid overwhelming the receiving servers, which can lead to emails being marked as spam or being temporarily or permanently blocked. Throttling can be managed by your ESP, which will distribute the sending load over a period to ensure better deliverability. It's essential to understand the limitations and guidelines set by your ESP and tailor your sending strategy accordingly. Proper email throttling helps in maintaining a good sender reputation and ensures higher deliverability rates.