The protocol you want to use.

C# |
public string Protocol { get; set; }

Supported protocols include:
- http -- delivery of JSON-encoded message via HTTP POST
- https -- delivery of JSON-encoded message via HTTPS POST
- email -- delivery of message via SMTP
- email-json -- delivery of JSON-encoded message via SMTP
- sms -- delivery of message via SMS
- sqs -- delivery of JSON-encoded message to an Amazon SQS queue