Json Webhook example

I need to get the email address from the chat and process it via a webhook written in PHP. Please provide me an example on how to achieve that. I have read the references but I am out of clues.

When I test the API url in postman it shows as below

{
"messages": [
{
"cards": [],
"date": "2018-03-26T15:26:06Z",
"from": "botsApiChannel:",
"id": 3212594,
"message": "Hey there, What's up. Do you need any help today ?"
},
{
"cards": [],
"date": "2018-03-22T17:14:36Z",
"from": "botsApiChannel:",
"id": 3144886,
"message": "Hey there, What's up. Do you need any help today ?"
},
{
"cards": [],
"date": "2018-03-22T15:48:41Z",
"from": "botsApiChannel:",
"id": 3143459,
"message": "Hey there, What's up. Do you need any help today ?"
}
],
"status": true
}

Your support is very valuable for me to resolve the issue. A small example will be much appreciated.

Thank you