Errors and Rate Limits
Errors and Rate Limits
Section titled “Errors and Rate Limits”The API uses HTTP status codes. Clients should handle rate limits and temporary failures without tight retry loops.
Common statuses
Section titled “Common statuses”| Status | Meaning |
|---|---|
400 |
The request is malformed or missing required data. |
401 |
The API key is missing or invalid. |
403 |
The account does not have access to the requested resource. |
404 |
The mailbox, message, or attachment was not found. |
429 |
The request exceeded a rate or quota limit. |
500 |
An unexpected server error occurred. |
Retry guidance
Section titled “Retry guidance”- Retry
429only after backing off. - Retry transient
5xxresponses with a capped delay. - Do not retry permanent
4xxvalidation or authorization errors without changing the request.
Free API limits
Section titled “Free API limits”Free accounts include a monthly request quota and per-minute rate limit. Upgrade when automated tests, QA suites, or agent workflows need higher volume.