Syntax for email data address?

Syntax for email data address?

userx-449@forms.zohocreator.com

Every form in an app has a unique email address to add a new record, right?  How does this work for an app that is sold in the Marketplace?  For instance what is the syntax of the email address then?

zoho-loginusername-formnumber@forms...

Does the form number change with each instance or does it remain the same?