Python Mailgun Question - 500 Internal Server Error

I am just learning Python and VS code and am in training.

Per Mailgun documentation, I have created a sendmail script (app.py) using Python:

def send_simple_message():
return requests.post(
    "https://api.mailgun.net/v3/YOUR_DOMAIN_NAME/messages",
    auth=("api", "YOUR_API_KEY"),
    data={"from": "Excited User <mailgun@YOUR_DOMAIN_NAME>",
          "to": ["bar@example.com", "YOU@YOUR_DOMAIN_NAME"],
          "subject": "Hello",
          "text": "Testing some Mailgun awesomness!"})

I run the Python script in Visual Studio Code from the terminal like so:

 Python app.py

When I test using Postman, the email is sending successfully, but in Postman, I am getting a 500 error and not exactly sure why:

<!doctype html>
<html lang=en>
<title>500 Internal Server Error</title>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error and was unable to complete your request.     
Either the server is overloaded or there is an error in the application.</p>

Still trying to get the gist of using VS Code, it seems to be a bit of a learning curve though.

Solution

The MailGun documentation/Python example that I used didn't seem to work as expeected:

def send_simple_message():
return requests.post(
    "https://api.mailgun.net/v3/YOUR_DOMAIN_NAME/messages",
    auth=("api", "YOUR_API_KEY"),
    data={"from": "Excited User <mailgun@YOUR_DOMAIN_NAME>",
          "to": ["bar@example.com", "YOU@YOUR_DOMAIN_NAME"],
          "subject": "Hello",
          "text": "Testing some Mailgun awesomness!"})

When I changed the code to the following:

@app.route('/notifications', methods=['POST'])
def notifications():
 r=requests.post(
    "https://api.mailgun.net/v3/blahblahblah.mailgun.org/messages",
    auth=("api", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"),
    data={"from": "Mailgun Test <postmaster@sandboxdxxxxxxx.mailgun.org>",
          "to": ["addressee", "mail@mail.com"],
          "subject": "Hello",
          "text": "Testing some Mailgun awesomness!"})
 
 return r.text

I received the following return: