I want to implement an pdf attachment to my invoice mail to the customer. I have a pretty good guess on how to do that, however this time I would like to solve the task with an event observer.
Not having worked much with Magento Observers before, I have some troubles figuring out which event to hook into.
What I need is an event which happens when the standard email is composed, so that I can simply attach my pdf copy of the invoice. Funnily enough all the helpful sites I found on the internet omit exactly on explaining that step in order to keep the tutorial generic or something.
Any hint about the event, or even better on a generic way to figure out the right event to use in any task, would be greatly appreciated. Thank you.