About activities in ReFramework

Hello everyone
As a fresh of Uipath, I wanna ask you a question about the REFramework!
Do you know why when I create a REFramework there will not be the activities about email under the App Integration?
Is there anything I need to set up?

Kindly install UiPath.Mail.Activities package
Go to Manage Packages → All Packages → Search for mail and install the package that you see on the screenshot by clicking on Install and Save

Thanks I will try
But it’s strange that when I open a Process there will be mail activities without further downloading and installing…do you know why