How to make customer Bill to contact email address mandatory

Summary:

 Can we make Bill to contact email address mandatory

Content (please ensure you mask any confidential information):

We have a business requirement as mentioned below:

Bill to contact Email address must be mandatory when creating a contact. The orders fail to get imported in Oracle as we have not made it mandatory. Data needs to be cleaned as contact in AR is coming up in Sales Cloud with no email address and it is causing sync issues.

Business impact: not having an email address on a contact means any order with one of these contacts will fail at some point. These contacts will not sync between systems.