> ## Documentation Index
> Fetch the complete documentation index at: https://docs.paubox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Limits and overage rates

> Sending limits, rate limits, and overage pricing for the Paubox Email API.

## Sending limits

| Limit                                       | Value |
| :------------------------------------------ | :---- |
| Max recipients per message                  | 100   |
| Max attachment size (total per message)     | 10 MB |
| Bulk messages (recommended max per request) | 50    |

<Note>
  For high-volume sends, use the [bulk messages](/email-api/bulk-messages) endpoint rather than looping over individual `/messages` calls. Paubox recommends batches of 50 or fewer messages per request.
</Note>

If you receive a `429 Too Many Requests` response, back off and retry. See [Errors](/email-api/errors) for retry guidance.

## What to do if you've reached your limit

You will be charged a small amount per-email for each email that you send beyond the limit of your current plan. Any overage charges will appear on an invoice of the month after any over-limit sending occurs.

## Paubox Email API overage costs

If you go over your plan limits, here’s a breakdown of the overage costs you’ll incur:

| **Plan Information** | **Monthly Plan Limits** | **Cost Per Extra Email** |
| -------------------- | ----------------------- | ------------------------ |
| Free                 | 300                     | -                        |
| Pro                  | 10,000 emails           | \$0.0130                 |
| Pro                  | 30,000 emails           | \$0.0130                 |
| Pro                  | 50,000 emails           | \$0.0100                 |
| Pro                  | 100,000 emails          | \$0.0098                 |
| Pro                  | Custom                  | -                        |