Shared Contacts
When you use Microsoft Office Outlook 2007 or higher with a Microsoft Exchange account, contacts can be shared. You can create additional contacts folders and choose which of those folders to share. For example, you can create a contacts folder for a specific project and share it with your coworkers. Optionally, you can grant them permission to modify the contacts.
Note: Any message, contact, or task in Outlook can be marked private so that others don’t see the item in shared folder.
Contact sharing works through sharing invitation and sharing request e-mail messages. Sharing invitations offer the recipient access to your contacts folder. When you send a sharing invitation for your default Contacts folder, you can request access to the recipient’s default Contacts folder.