Gmail EventReservation markup disappearing - gmail

Question

My EventReservation markup has been approved by Google but I'm noticing that at times, the ViewAction (a simple link) that I associated with it disappears from Gmail and I was wondering what could cause this problem.
Markup example:
{
{
"#context":"http://schema.org",
"#type":"EventReservation",
"reservationStatus":"http://schema.org/Confirmed",
"reservationNumber":XXX,
"url":"XXX",
"action": {
"#type":"ViewAction",
"name":"Message Host",
"url":"XXX"
},
"modifiedTime":"2015-08-13T17:56:29+0000",
"underName": {
"#type":"Person",
"name":"XXX"
},
"reservationFor": {
"#type":"Event",
"name":"XXX",
"image":"XXX",
"startDate":"2015-08-17T10:42:28-0400",
"endDate":"",
"location": {
"#type":"Place",
"name":"",
"address": {
"streetAddress":"XXX",
"addressLocality":"XXX",
"addressRegion":"XXX",
"postalCode":"XXX",
"addressCountry":"XXX"
}
}
}
}

Answer 1

There are a few ways to generate a button with the EventReservation schema. You can generate a "View Ticket" button using a URL property:
"url": "https://example.com"
To get a "modify reservation" button, use the modifyReservation property:
"modifyReservationUrl": "https://example.com
In the example you've posted, I'm assuming you're trying to trigger a custom action label with the ViewAction schema. I was able to achieve this by defining a top level Event Reservation first then the View Action. My example below:
<script type="application/ld+json">
{
"#context": "http://schema.org",
"#type": "EventReservation",
"reservationNumber": "123456",
"reservationStatus": "http://schema.org/Confirmed",
"underName": {
"#type": "Person",
"name": "John Smith"
},
"reservationFor": {
"#type": "Event",
"name": "Example Event",
"startDate": "2015-08-17T14:30:00-08:00",
"location": {
"#type": "Place",
"name": "AT&T Park",
"address": {
"#type": "PostalAddress",
"streetAddress": "24 Willie Mays Plaza",
"addressLocality": "San Francisco",
"addressRegion": "CA",
"postalCode": "94107",
"addressCountry": "US"
}
}
},
"potentialAction": {
"#type": "ViewAction",
"name": "View Event",
"target": "https://www.example.com"
}
}
</script>
The action button doesn't disappear and should stay:

Answer 2

json+ld markup is also removed by some eMail carriers.
I found Mandrill was removing my markup, until I changed the format from json+ld to microdata.