curl --request GET \
  --url https://api.railmail.app/api/v1/campaigns \
  --header 'X-API-Key: <api-key>'

{
  "data": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "campaignKey": "<string>",
      "name": "<string>",
      "subject": "<string>",
      "previewText": "<string>",
      "contentJson": "<string>",
      "contentText": "<string>",
      "status": "<string>",
      "sendStrategy": "<string>",
      "topicIds": [
        "3c90c3cc-0d44-4b50-8888-8dd25736052a"
      ],
      "segmentIds": [
        "3c90c3cc-0d44-4b50-8888-8dd25736052a"
      ],
      "estimatedRecipientCount": 123,
      "scheduledAt": "2023-11-07T05:31:56Z",
      "completedAt": "2023-11-07T05:31:56Z",
      "fromEmail": "<string>",
      "fromName": "<string>",
      "preSendScore": 123,
      "preSendStatus": "<string>",
      "createdAt": "2023-11-07T05:31:56Z",
      "updatedAt": "2023-11-07T05:31:56Z"
    }
  ],
  "pagination": {
    "page": 123,
    "size": 123,
    "totalElements": 123,
    "totalPages": 123,
    "hasNext": true,
    "hasPrevious": true
  }
}