Instantly is an email marketing platform that allows users to create and send email campaigns and track their performance. It offers basic features such as list management, email templates, and reporting. SalesHandy, on the other hand, is a comprehensive email marketing platform that not only offers email campaign creation and tracking but also includes email automation, lead generation, and contact management features. SalesHandy also provides email tracking and analytics, sales engagement, and email personalization features. Overall, SalesHandy offers more advanced features than Instantly and is a more comprehensive solution for email marketing and sales engagement.