# Send API JSON properties

The main content of the Send API payload will be the `Messages` property, which is a collection of messages, represented as a JSON array. This is the only mandatory property within the payload.

Additionally, you can use the [`Globals` property](#set-global-payload-properties) to specify values for properties to be applied to all objects within the `Messages` array.

Finally, you can enable [Sandbox mode](#sandbox-mode) by setting the `SandboxMode` property to `true`.

Full descriptions of the properties of each message can be found in the [Email API reference](/docs/api-reference/email-api/categories/send-emails/#v3_post_send)