1. Using a web browser, navigate to https://mail.zimbraservice.com and log into the desired mailbox.
2. Select the Address Book tap.
3. Under New, choose the drop down arrow and select Contact Group.
4. When the New Contact Group window appears, Type in the Group Name and which Address Book will the contact group be placed in.
5. On the right hand side, under "Add Members to this Group, choose the address list that contains the desired users. you will be able to choose either your Global Address List, Contacts and Personal and Shared Contacts. Once you have selected the contact list, highlight and add each contact you wish to be in the group.
6. Select Save to complete your contact group.