If you manually add a new user to Impraise or view that users haven't registered on the Activity page, you can re-send the invitation email with a new link to register.
Sending Invites to Unregistered Users
First, select User Management from the left-hand navigation bar.
Make sure to change the sorting from Hierarchy to A-Z List.
All unregistered users have a note next to their names in the user list Not invited or Not registered.
Scroll and select the User to invite.
On the right, you will see the Users details. Scroll to the Account details section.
The date of the last invitation email is shown. Click 'Resend invitation email' to send an additional email invite.
Tip: If multiple invitation emails are sent, only the most recent invitation will be valid.