Rate limiting controls how many requests a user can make in a time window. Learn why rate limiting prevents abuse and protects deliverability and infrastructure.
Rate limiting is a technique used to control how many actions or requests a user or IP address can perform within a set time window. It protects servers and APIs from abuse, spam-like behavior, and traffic spikes that could degrade performance.
In email tooling, rate limiting is especially important for features that can be abused, such as email verification, website email extraction, or any endpoint that performs expensive DNS or network lookups. Limiting requests helps keep services stable for legitimate users.
Good rate limiting is practical and user-friendly. It should provide clear error messages, reasonable thresholds, and escalation strategies such as requiring authentication or CAPTCHA only when suspicious patterns are detected.