Although it is possible to contact someone via Lync without adding them as a contact, adding them to your contact list is useful if you message certain people very regularly. Lync is linked to the same Address Book as Outlook. However, your personal contact list is kept separately.
If you have only recently set up Lync, the Global Address List may not have had time to sync. Therefore, searching for a contact may not yield any results. This can be fixed by waiting for the system to automatically update your list of contacts, or manually updating the Global Address List.
PC Users: Right-click on the name and select Add to Contacts List and then choose the Contact Group you would like to place them in.
Mac Users: Click on the Plus Icon to the right of the contact, and then select the Contact Group you would like to place them in.
When you add a contact to your list, the person you have added will be notified via Lync that they have been added. They can then choose to add you to their Contacts List also.
A number will appear next to the "Contact" icon on the main screen of Lync. Clicking on this icon will allow you to view the contact and follow the above steps to add them to your Contacts List.
Right-clicking on the user's name will also give you the option to block the person from contacting you, or simply remove the notification.
A pop-up window will notify you that you have been added to a Contacts List. You are then given the option to add them to your Contacts List, cancel the notification, or block the user from contacting you.