The principle behind sharing contacts - and certainly contact groups - is to create a new folder and put the contacts to be shared in there. Then share the folder.
For more detail, the following is taken from a University of Sussex post:
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How to share an Outlook contact group
This article is for members of staff and researchers who have their email hosted on the Exchange system.
A contact group acts like a mailing list, but remains internal to Outlook and Exchange, and is private to you unless shared with others.
If you have a contact group containing a number of addresses of a group of people you email repeatedly, it is possible to make the contact group available to other named Exchange users so that they can also use it to email the same people. However, the contact group can only be made available to others by making its containing contacts folder a shared folder. For this reason it is best to keep contact groups in folders of their own, so that no other contacts information is made accessible to others.
Note also that the contact group and its containing folder will only be available to other Outlook users on the Exchange system. It will not be available to those using other email applications.
The basic steps involved are:
Each step is described in detail below (these instructions assume the use of Outlook 2010):
Create a contacts folder for the contact group
Create the contact group
The procedure for creating a contact group and adding members to it is described separately in FAQ 2314 (start from step 2). The instructions are separate because contact groups might want to be set up for personal use only.
If your contact group has already been set up in another contacts folder, you can move it to your new folder by means of drag-and-drop.
Share access to the new contact folder with other people
The invited persons will receive an email with the Subject line "Sharing invitation:" and giving the name of the sharer and the name of the contacts folder being shared. At the top of the message there will be a button to "Open this Contacts folder". Clicking the button confirms the invitee's acceptance, and the shared folder should then become visible in their Contacts list, under a heading labelled Shared Contacts. The invitee can then open the folder and access the contact group within.
Note how the icon for a contact folder changes from to once it has been made shareable.
Article ID: 151
Created On: Fri, Jun 30, 2017 at 11:46 AM
Last Updated On: Fri, Jun 30, 2017 at 11:46 AM
Online URL: https://knowledgebase.stickman.co.uk/article.php?id=151