Where are in magento 1.8. core functions for sending emails?

Question

If I change or delete app/code/core/Mage/Core/Model/Email/Template.php email still working and sending. I need modify that functions, but my modifications have not affect.

I uninstalled all the modules, there are no modules in app/code/local , app/code/comunity .

Cache deleting have no effect.

Where else are or can be those functions?

In 1.7. everything works fine.

Answer 1

Solved, problem was in Magento compilation tool .

Not only cache to show results, but needed to disable compiler too, eventually rename or delete ROOT/includes/ folder in Magento.

After that all new scripts should be available.