Each Project Mapping is mapped against a specific Project. This is selected in the Project Mappings ‘Project' section.
Project
This is the Project selection. Selecting a different Project will begin mapping matching incoming messages to the newly selected configuration.
Project Association By Email Address
When enabled, the catch email address that the email is sent to will be checked for a project key. If the catch email address contains a valid Project Key when this setting is enabled, Issues will be created in the found Project.