Limits & Quotas
API, payload, and Gmail quotas.
Limits keep QuickSend stable and Gmail happy. We meter where Google meters.
API Rate Limits
| Endpoint | Limit | Window |
|---|---|---|
| POST /api/send | 30 / min | per key |
| POST /api/batch | 5 / min | per key |
429 Too Many Requests + Retry-After when exceeded.
Payload Limits
| Field | Limit | Notes |
|---|---|---|
| subject | 998 chars | RFC 2822 |
| html | 2 MB | UTF-8 |
| text | 1 MB | UTF-8 |
| to/cc/bcc | 50 each | string or array |
| attachments | 5 × 1 MB | 25 MB total cap |
Daily Gmail Quotas (Google's hard cap)
| Account | Free | Notes |
|---|---|---|
| @gmail.com | 500 / day | Resets UTC midnight |
| Workspace | 2,000 / day | Resets UTC midnight |
Batch respects the same caps: 450/batch personal, 2,000/batch Workspace.