# Send Email Campaign

POST /api/v2/projects/{projectId}/email-campaigns/{campaignId}/send

Starts sending a campaign to its audience. The campaign is validated first (missing subject, sender, or audience returns 400 with the specific problems listed) and the project must have an unblocked sender and enough balance. Sending then runs in the background in batches, so a 200 means the send has started, not that it has finished; poll Get Email Campaign for progress. Emails already on their way cannot be recalled.

## Request

- projectId: string, path, required — ID of the project that owns the campaign.
- campaignId: string, path, required — ID of the campaign to send.

## Response

- 200: Successful response
  - message: string, required
- 400: Invalid input data
- 401: Authorization not provided
- 403: Insufficient access
- 500: Internal server error