You can share documents for co-authoring with external collaborators who do not exist in the iManage Work Server. To collaborate, you must set up One Drive for Business. For more information, see Installing the Co-Authoring Add-On and Co-Authoring FAQ.
If the external collaborator's email is not in the firm's Office 365 email directory, Microsoft sends an invite directly to the user, and you can view it in your sent items folder. If you review the email invite in Outlook, the external users' email IDs do not appear in that email message. If an external user is in the firm directory but not registered in the iManage Work Server, the user's email address appears in the email invite.
If you reopen the Invite people dialog box to invite more users, the external users email addresses are displayed in the Shared with list.
The external collaborator receives an email that contains a link. The collaborator can select the link, and then enter their Office 365 account credentials when prompted to open the document. You receive an email notification when the external collaborator accesses the document.
External collaborators are referenced by their emails addresses in the Revision History and Timeline of co-authored documents. For more information, see Viewing the document revision history.