# The 60-Minute Inbox Audit with Corné van Willigen

> What You'll Get ✅ 60-Minute Private Video Call Work directly with an email deliverability expert. ✅ Deliverability Health Check Review your sending setup, domain authentication, list health, and potential inbox placement issues. ✅ Find Your Hidden Problems Discover what could be causing your emails to land in spam, get blocked, or simply go unnoticed. ✅ Your Personal Action Plan Leave knowing exactly what to prioritize to improve your email deliverability. ✅ Ask Anything Get expert answers to your specific deliverability questions. No generic advice.

- Host: Corné van Willigen
- Duration: 60 min
- Location: Cal Video
- Host time zone: Europe/Amsterdam
- Confirmation: Bookings are confirmed instantly.
- Payment: required, and collected on the booking page.
- Booking page: https://cal.com/corne-van-willigen-v4aabj/the-60-minute-inbox-audit
- Event type id: 7831993

## Check availability

```http
GET https://api.cal.com/v2/slots?eventTypeId=7831993&start=YYYY-MM-DD&end=YYYY-MM-DD&timeZone=<IANA time zone>
cal-api-version: 2024-09-04
```

The response is `{"data":{"YYYY-MM-DD":[{"start":"<ISO 8601 with offset>"}]}}`; no API key is needed.

## Book

```http
POST https://api.cal.com/v2/bookings
cal-api-version: 2026-02-25
Content-Type: application/json

{
  "eventTypeId": 7831993,
  "start": "<UTC ISO 8601 start from the slots response>",
  "attendee": {
    "name": "…",
    "email": "…",
    "timeZone": "<IANA time zone>"
  },
  "guests": [
    "guest@example.com"
  ],
  "bookingFieldsResponses": {
    "attendeePhoneNumber": "…",
    "notes": "…"
  }
}
```

- Required fields: `name` (Your name), `email` (Email address)
- Optional fields: `attendeePhoneNumber` (Phone number), `notes` (Additional notes), `guests` (Add guests)
- `name` and `email` go in `attendee` and `guests` is a list of emails; every other field goes in `bookingFieldsResponses` under its name.