Exchange Server users or Microsoft 365 Business subscribers can share a contact folder with another person inside and outside of the
organization if sharing contact lists is supported by the organization's sharing policies. If you do not
have an Exchange Server account or your organization policies do not allow contact folders sharing,
Microsoft Outlook does not offer the Share Contacts option. However, you can share contact lists,
email groups, or distribution lists by
creating the contact group,
attaching it to the email, sending the email, and importing.