When sending a TMail to the Writers who are not in your favorite list, you have an option to add them as a favorite Writer. If you use an Organization Account Type, all the Writers who are part of your organization are part of your favorite list, by default. (Please see Account Types for more details on the Organization account type.)
When you send a TMail to the Writers who are not in your favorite list, the Add to Favorite list tab appears as below.
Select the Writer whom you want to add to the favorite list. Click on Add button.
When you add this writer in Add Writers, the name automatically appears as you start writing the name, as below.