I hope this question is OK to ask here, given that it could replace my usage for Google Calendar API I think it should be OK.
https://stackoverflow.com/help/on-topic
When you get an email about an event like a flight, concert, or restaurant reservation, it's added to your calendar automatically.
https://support.google.com/calendar/answer/6084018?co=GENIE.Platform%3DDesktop&hl=en
I think this is a really neat feature but I would like to know If I can create an email that will automatically show up in my calendar myself. I'm currently using the Calendar API, Google.Apis.Calendar.v3, but if I could get this to work my application would not need to handle credentials anymore which would be really great.
Cases where the email won't show up according to support page:
Events won't show up if the email was:
- Sent to a mailing list
 - Sent to you by cc
 - Redirected from another email account
 
Events are only added if they are in confirmation emails from businesses about:
- Flights
 - Hotels
 - Restaurants
 - Ticketed events like movies and concerts
 
I have been reading up on Events from Gmail and created the sample below.
https://developers.google.com/gmail/markup/google-calendar
https://developers.google.com/gmail/markup/getting-started
https://developers.google.com/gmail/markup/reference/event-reservation
<html>
<body>
    <script type="application/ld+json">
        {
        "@context": "http://schema.org",
        "@type": "EventReservation",
        "reservationNumber": "E123456789",
        "reservationStatus": "http://schema.org/Confirmed",
        "underName": {
        "@type": "Person",
        "name": "Oscar Andersson"
        },
        "reservationFor": {
        "@type": "Event",
        "name": "Foo Fighters Concert",
        "performer": {
        "@type": "Organization",
        "name": "The Foo Fighters",
        "image": "http://www.amprocktv.com/wp-content/uploads/2027/01/foo-fighters-1-680x383.jpg"
        },
        "startDate": "2019-05-08T19:30:00-01:00",
        "endDate": "2019-05-08T23:00:00-01:00",
        "location": {
        "@type": "Place",
        "name": "AT&T Park",
        "address": {
        "@type": "PostalAddress",
        "streetAddress": "AT&T Park",
        "addressLocality": "San Francisco",
        "addressRegion": "CA",
        "postalCode": "94107",
        "addressCountry": "US"
        }
        }
        },
        "ticketToken": "qrCode:AB34",
        "ticketNumber": "abc123",
        "numSeats": "1",
        "modifiedTime": "2019-05-07T15:15:00-01:00",
        "modifyReservationUrl": "http://united.com/modifyreservation.html"
        }
    </script>
    <p>
        Dear Oscar, thanks for booking your Google I/O ticket with us.
    </p>
    <p>
        BOOKING DETAILS<br />
        Reservation number: IO12345<br />
        Order for: Oscar Andersson<br />
        Event: Google I/O 2013<br />
        Start time: May 15th 2013 8:00am PST<br />
        Venue: Moscone Center, 800 Howard St., San Francisco, CA 94103<br />
    </p>
</body>
</html>
I have validated the markup with Email Markup Tester from Google and it says No errors detected. Then I imported the HTML above from Notepad++ to Outlook via Run -> Send via Outlook and sent it to my Gmail. I received the email but the Calendar event was not present.
https://www.google.com/webmasters/markup-tester/
According to their documentation All schemas you send to yourself (from x@gmail.com to x@gmail.com) will be displayed in Google products. but I can't see the event.
https://developers.google.com/gmail/markup/registering-with-google
I have tried creating my own program to send the email via Gmail servers to myself but the events still don't show. Tried copying a lot of the events mentioned on their guides and reference page.
var emailAddress = new MailAddress("myGmail@gmail.com", "Ogglas");
SmtpClient smtpClient = new SmtpClient();
smtpClient.Host = "smtp.gmail.com";
smtpClient.Port = 587;
smtpClient.EnableSsl = true;
smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
smtpClient.UseDefaultCredentials = false;
smtpClient.Credentials = new NetworkCredential("myGmail@gmail.com", "mySuperSecurePassword789&");
MailMessage mailMessage = new MailMessage();
mailMessage.From = emailAddress;
mailMessage.To.Add(emailAddress);
mailMessage.Subject = "Concert test";
mailMessage.IsBodyHtml = true;
var currentPath = Directory.GetCurrentDirectory();
var htmlEmail = File.ReadAllText(currentPath + "\\Email.html");
mailMessage.Body = htmlEmail;
smtpClient.Send(mailMessage);
Example from a flight how I would like it to look:
Gmail:
Calendar:
Example from booking.com
Has anyone here managed to get this working?


