Here are several steps to ensure keyboard accessibility in your email marketing:
Use semantic HTML elements like <a> for links and <button> for buttons to ensure they are inherently keyboard accessible. Ensure that all interactive elements, such as links and buttons, are reachable and operable using the Tab key. This can be tested by navigating through your email using the Tab key alone. Provide clear focus indicators for interactive elements to ensure users know which element is currently selected. Implement ARIA roles and attributes where necessary to enhance accessibility for assistive technologies.