Can you provide real-world examples of businesses that have successfully used this Python script for their email marketing strategies?

Some potential challenges or drawbacks of having to log in each time you use the Python script for sending emails could include the inconvenience of having to remember and input your login details each time, which can be time-consuming. Additionally, if you're not using a secure connection, there's a risk that your login details could be intercepted. Finally, if the script fails to log in correctly, it could prevent the emails from being sent.

The Google API connection in the Python script offers a high level of privacy and security compared to other methods. When using this method, no extra SMTP details are required. The Google API manages everything, establishing the connection automatically when the Python script gets executed. The only requirement is to sign in to your Gmail or Google Worksuite account as usual. Login details aren't stored or saved, so you'll need to log in each time you use the script. This ensures that your information remains private and secure.