Helo.configure do |config|
  config.access_token = "YOUR_BEARER_TOKEN"
end

opts = {
  channel_id: "550e8400-e29b-41d4-a716-446655440000",
  after: 10,
  start_date: "2024-01-01T00:00:00Z",
  end_date: "2024-01-01T00:00:00Z",
  limit: 10,
  recipient: "example",
  subject: "example",
  tags: ["example1", "example2"],
  mail_type: "transactional",
  status: "sent"
}
Helo::Activity.list_messages(opts)

{
  "totalCount": 123,
  "results": [
    {
      "messageId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "channelId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "timestamp": "2023-11-07T05:31:56Z",
      "subject": "<string>",
      "recipients": [
        "<string>"
      ]
    }
  ],
  "after": 123
}