title: Effectively using Google App Engine to send lots of emails using PHP?
body: <p>I currently have a client website on the Grid server on MediaTemple that will be moved to a Virtual Private Server soon. Currently it's using some hacks to trickle his massive email sendouts using cron jobs and queuing with the database (to avoid going over the limit MediaTemple set). </p>
  
  <p>We can't use third party solutions (like MailChimp etc) as the price is just too much for the client to pay (he has 75,000+ people on his mailing list). So after lots of research, I've found that using Google App Engine as basically a scalable way to send out lots of emails is a viable option.</p>
  
  <p>His site uses PHP at the moment. I do eventually want to use Python/Django, but not for the time being... There is a few things I don't quite understand... Such things as having the app called 'example.appspot.com', can this be a sub domain on his site (like mailapp.example.com)? After reading the user guide on Google App Engine it seems that the email address the app uses is an admin on the application (like admin@example.appspot.com)... that has to be that? It can't possibly be something like example@example.com?</p>
  
  <p>I understand that sending out so many emails means I'll have to enable the billing on the application. I understand there is still a quota on how many I can send. I've even seen this code that could help set this up easily: <a href="http://github.com/tow/appengine-mailer" rel="nofollow noreferrer">http://github.com/tow/appengine-mailer</a></p>
  
  <p>I ideally want to replace the PHP code where it sends out email (using mail() etc) and make it send out with Google App Engine instead.</p>
  
  <p>Has anyone successfully done this sort of setup? Can anyone help me spell the steps required? Or provide any pitfalls to using such a system?</p>