I have imported "smtplib" in the code, and I doubt that the server won't have this installed. Is there a CDN for modules in python ?
You should save your dependencies in a requirements.txt file and use pip to install the requirements as part of your Django app's deployment process.
Edit: smtplib is part of the standard lib, so it should be available out of the box.
What if the hosting Django server don't have the module I imported?