Magento Core Functions and Classes SmtpPlus is overriding

SmtpPlus is overriding some Magento Core Classes. So when experiencing conflicts with other Extensions, or having lost store customizations with SmtpPlus being installed, these are the Classes it is overriding from the Magento Core:

Magento Core Classby DownloadPlus rewritten toRemarks
Mage/Core/Model/Email.phpPisc/Smtpplus/Model/Email.phpTo extend the core Email class.
Mage/Core/Model/Email/Template.phpPisc/Smtpplus/Model/Email/Template.phpTo extend the core Email-Template class.

In case of Magento Core classes overridden by other extensions, or own customizations, be aware that you might need to consolidate these changes into one of these classes. To keep the SmtpPlus functionality in such case.