Mailshake is primarily an email marketing tool that focuses on email outreach campaigns to generate leads and increase sales. It offers personalized email templates, email tracking, and automation features for follow-ups and scheduling emails. On the other hand, Intercom is a CRM platform that focuses on customer communication, engagement, and support. It offers live chat, email, and social media messaging features, as well as customer relationship management tools for managing a customer database, tracking leads, and measuring engagement. While Mailshake is best suited for small to medium-sized businesses looking to optimize their email outreach campaigns, Intercom is ideal for businesses looking to communicate with customers in a personalized, multi-channel way for sales, marketing, and support.