If you are using Active Directory with your mail server to manage user accounts, there is no need to manually create user accounts in Mail Express. When you are connected to an Active Directory (AD) user database, the Internal senders page is automatically populated. Active Directory users are created as Internal users upon their first login to Mail Express. However, you can manually create users in Mail Express and allow them access to the Mail Express web portals. Mail Express can have up to 500,000 external users, 25,000 Internal users, and 25,000 administrator users.
Mail Express has the following types of user accounts:
Administrators—Administrator accounts are created during installation and later in the Mail Express Server Administration portal. There are no "granular" administrator permissions; Each administrator account has access to all of the settings in the Mail Express Server. Administrator credentials cannot be used to access any portal other than the Administration portal.
Internal users—Internal users are users within your organization who can send email attachments to users inside and outside your organization using the Mail Express Outlook Add-In or the internal users' web portal. Only internal accounts are valid for connecting to the Mail Express Server with the Outlook Add-In. Internal users can change their Mail Express password via the web portal (unless the user was created in Active Directory). Optionally, internal users can have access to the Drop-Off portal, send account invitations, and include reply links in their emails.
External users—External users are users outside your organization; they do not have an account on your mail server. External users access Mail Express from the Drop-Off portal to pick up attachments sent to them from internal users. The external user's send files permission can be enabled or disabled by the administrator. (It is enabled by default.)