These are what WizyGmail requires:
View and manage your email. This lets you do the following:perform email scheduling, mail merge, reminders and snooze; send invitations; see recent conversations and analytics in your sidebar. WizyGmail does not store the body of your emails.
View basic profile info. This allows WizyGmail to display your email and name.
View the files in your Google Drive. This makes it possible for you to import spreadsheets for mail merges.
Manage your contacts. This is so you can manage your contacts inside your Gmail.