Understanding Ticket Security

Hi everyone.

I need some help understanding ticket security.

There are several clients who send me work related requests through an e-mail I would prefer to be kept for general business correspondence. I thought it would be convenient to pipe those e-mails through the WHMCS ticket system so that they can be re-directed to the proper department -- it's all me doing all of the work, but the ticketing system allows me to keep things more organized.

So I just received an e-mail from someone to my general-correspondence address. I got a copy of the e-mail in my inbox, and a copy of it also appears on the web in the ticket system even when the user has no account. If anyone has the link the ticket, the semi-private e-mail, can be viewed by the public.

I have a dedicated support e-mail that within Setup > Support Ticket Departments > Edit Department that has Clients Only checked (turned on). Those tickets are not available to the public and require a logon to the system before they can be viewed.

Is there a way I can keep general inquiries piped through the system hidden even when the sender does not have an account?

Thanks