Several tools can assist you in creating and testing mobile-responsive emails. Some popular options include:
Mailchimp: Offers responsive templates and a built-in preview tool. Campaign Monitor: Provides a variety of responsive design options and testing tools. HubSpot: Features responsive email templates and a comprehensive testing suite. Litmus: Allows for thorough testing across multiple devices and email clients. Email on Acid: Offers extensive testing and troubleshooting features.