Send a HTTP request to another PostalPoint installation on the local network.
**Kind**: static method of [<code>httpserver</code>](#httpserver)
**Returns**: <code>Promise.<Object></code> - - The JSON reply.
**Throws**:
-<code>Error</code> When there's a network or other unrecoverable error while completing the request. Error message is a human-readable description of the problem.
| Param | Type | Description |
| --- | --- | --- |
| data | <code>Object</code> | Data to encode as JSON in the request body. |
| endpointID | <code>string</code> | Endpoint to call. |
| serverAddress | <code>string</code> \| <code>undefined</code> | Address of the PostalPoint server. If undefined, uses the host address configured in PostalPoint's Databases settings. |
| serverPort | <code>number</code> \| <code>undefined</code> | Port of the PostalPoint server. If undefined, the default PostalPoint port number is used. |