These are the options I see at the moment.
1 - Create a table that will have the PDF attached to the record in that table then create a notification when a record is created in that table and have it trigger a notification and check the include the attachments box on the Notification.
2 - Create a record directly in the sys_email table and attach the attachments that way,
3 - Format the notification is such a way that when it is created in the sys_email table you can trigger a business rule when the record is inserted that will create the pdf and attach it to the record.
More options maybe available depending on how the notification is triggered or what is triggering the notification.
