Connect ETIMEDOUT error using POSTMAN with NEWMAN

I'm using Newman in order to execute a POSTMAN collection but I always have the
error "connect ETIMEDOUT". Using just POSTMAN it works fine, but not with NEWMAN.
The testing is quite simple, create a content on the server
https://jsonblob.com/api

I'm following the tutorial
http://blog.getpostman.com/2014/04/17/how-to-write-automated-tests-for-apis-with-postman-part-2/

Thanks you very much in advance. I put below the collection and the enviroment file.

This is the collection:
{
"id": "a6a6b2fe-db11-4c57-9144-6b3324174f18",
"name": "Newman",
"values": [
{
"key": "url",
"value": "https://jsonblob.com",
"enabled": true,
"type": "text"
},
{
"key": "deviceMapping",
"value": "{\n \"content\": \"My first blog post :)\"\n}",
"enabled": true,
"type": "text"
},
{
"key": "blogLink",
"value": "https://jsonblob.com/api/jsonBlob/b7f2ce87-4c8e-11e8-917b-9137e61d314b",
"enabled": true,
"type": "text"
}
],
"_postman_variable_scope": "environment",
"_postman_exported_at": "2018-04-30T16:13:07.630Z",
"_postman_exported_using": "Postman/6.0.10"
}

This is the enviroment file:
{
"id": "a6a6b2fe-db11-4c57-9144-6b3324174f18",
"name": "Newman",
"values": [
{
"key": "url",
"value": "https://jsonblob.com",
"enabled": true,
"type": "text"
},
{
"key": "deviceMapping",
"value": "{\n \"content\": \"My first blog post :)\"\n}",
"enabled": true,
"type": "text"
},
{
"key": "blogLink",
"value": "https://jsonblob.com/api/jsonBlob/b7f2ce87-4c8e-11e8-917b-9137e61d314b",
"enabled": true,
"type": "text"
}
],
"_postman_variable_scope": "environment",
"_postman_exported_at": "2018-04-30T16:13:07.630Z",
"_postman_exported_using": "Postman/6.0.10"
}