When you send an email, the mailer communicates with a remote server in charge of receiving the message and of delivering it to the recipient. This process can cause your form to submit slowly as it depends on how fast the mail server responds. Spooling allows us to decouple the application execution line from the process of the sending one, two, or as many emails as we need.

They show you how to configure the SwiftMailerBundle with the mail server's settings, how to set up the command to send the emails and the settings you'll need to put in your cron file to run the "send" operation periodically.

Zend Core for i5/OS provides the i5 Toolkit for PHP, an API system to call i5 functionalities from PHP. One of the function of this API is the i5_spool that is able to manage spool files for specific i5 users. In this post I present a class to convert a spool file in PDF using the Zend_Pdf class of the Zend Framework.

He includes the quick twelve line code you'll need to get the job done. It reads in the spool file with some built-in functions and calls the "toPdf" method to export the result. There's also a few parameters you can include as a second parameter that let you define things like font size and margins.