The Salesforce Add-in for Outlook installs a button on the Microsoft Outlook toolbar to enable you to perform integrated functions between Outlook Desktop and Salesforce.
In Outlook, navigate to File > Info and select Manage Add-ins
You will be taken to Outlook Online. If you're not currently signed in to your Adler account, you will be prompted to do so. If you're currently signed in to another Outlook account, please sign out or use a different browser profile. Outlook Online will show you a list of Add-Ins for Outlook.
Search for Salesforce and select Salesforce.
Select Add on the Salesforce page. Once you've installed it this page will say Added in the place of Install.
Outlook will notify you that the Add-In has been installed. Close and re-open Outlook Desktop. When you open it, you should see a Salesforce Icon on the far right of the toolbar.