TraceMail is licensed on a ‘per user, per month’ basis, similar to the licensing of Microsoft CSP, and the customer is only charged for professional users, not guest users. Professional users can invite other users (guests) and can communicate securely with any end user from any organisation. Guest users have some restrictions, being that they can only create secure communications with the organisation (domain name) that invited them. They cannot invite other users and they cannot send secure messages to 3rd parties. Guest users that have not accessed the platform for 90 days will be disabled.