When using Hunter’s Campaigns feature with a connected Outlook or Gmail account, you may receive an "Error" sending status for some emails.
Below are the most common status error codes, what each means, and how to address them.
Error Code | Description | Common Causes | Suggested Remedies |
400 | "The server responded with status 400" | Custom email setup (e.g. hybrid Exchange, nonstandard configuration) | Verify your email server setup, check custom Outlook/Exchange configuration, contact Microsoft support if needed |
429 | "The server responded with status 429" | Too many API requests or rate limit exceeded | Slow down send rate, reduce number of emails sent, review email sending from other apps, check Gmail/Outlook sending rate limits |
Need more help regarding errors? Get support via chat or email (contact@hunter.io).