Send Zoho Invoice from a specific email address

Hi,

I'm looking over the directions for sending an invoice to a customer on http://www.zoho.com/invoice/help/invoices/online-invoices1.html#sending-an-invoice-to-a-customer .

I need clarification on the 'From' field for the invoice email. Does it allow you to set any 'From' email address or does it have to be from a @zoho.com email address?

Thanks