We allow anonymous customers.  We also take support cases online and the customer can create a support case at our web-store (when they are not logged in as a customer).  If the customer isn't logged in or has never been to our site, their support case will say "Company = anonymous customer" when we view it through the NS back-end.

The form on our web store requires this information...

Name:
E-mail:
Phone:
Subject: 
Question:

Here is the ODD thing.  The case has the customer's correct email (that they entered when filling out the online form), BUT it doesn't use that email address if we click the email shortcut along the top edge of the form.  If we respond to the case through the case-form's "messages tab" ...it works properly ...but not through the email link (which we use to send emails with attachments).  Instead of pulling up an email message with the correct address that the customer entered, it opens an email with the last saved email address used in the "anonymous customer placeholder".