The project name is set during project creation. It is from then on referenced multiple times in the database, so changing the project name is not a trivial task.
Once you are done evaluating and you create a new project for the actual development of the new site you will be able to set the project name to the one you need.
If you want to change the project name in the email notifications for the current project, then what you should do is change the template used for generating the message. You can check this
article for instructions on how to use your custom template for the email notifications.
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