Hi Neel,
You can't create a new one, instead you can edit the existing email templates. Follow the steps given below:-
1. In the Sourcing event go to Summary tab under Customized Message choose Customize
2. Select the message you want to edit and click on Customize.
3. Save it once the changes are done
If you want to do the same changes for all your projects, make these changes in the template.
Regards,
Aditya