Throttling is when mail servers limit how quickly you can send or deliver messages. Learn why throttling happens and how to reduce it.
Email throttling happens when a receiving provider limits how many messages it will accept from a sender within a certain period. This is a common anti-spam and stability measure that helps providers control traffic and reduce abuse.
Throttling can lead to delays, temporary SMTP errors, and slower campaign completion times. It often occurs when sending volume spikes, when reputation is weak, or when a provider wants to see more consistent behavior.
To reduce throttling, warm up sending identities, spread sends over time, and focus on engaged recipients. Strong authentication and low complaint rates help providers trust your mail and accept it more smoothly.