Google App Engine send batch email
You can set up a CRON job to run every few minutes and process your email queue. It will require an endpoint where you can send a POST request, but you can use a secret token (like just any random guid) to verify the request is legitimate before you send the email.
I was wondering how I would go about emailing user emails stored in a python datastore. 
Should I create a sort of maintenance page where I can log in as an administrator and then send an email or is there a way for me to execute a python script without needing a handler pointing to a separate webpage so I don't have to worry about the page being discovered and exploited.