When you want to save an email to NetSuite the first step is to click on the email. The second step is to click the Celigo button for the app to open. Typically it will bring you to a welcome page and ask you if you want to Attach an email to NetSuite or Search NetSuite (as shown below).
You now have the option to not show the welcome page at all by checking "Don't show the welcome page". Now when you click on an email that you want to save to NetSuite and click the Celigo button, it will skip over the above page completely and bring you to the Attach Email To NetSuite Records screen where it will start searching for Customers, Vendors and Contacts right away (see below). It eliminates the extra click to save your email.
If you ever want to re-enable this setting, go to settings and then check off enable landing page as shown below.