Inconsistent Fonts: Different email clients may not support the same fonts, leading to inconsistencies in the appearance of your emails. Broken Layouts: Complex layouts may not render correctly across all email clients, causing misalignment and broken elements. Image Display Problems: Some email clients block images by default, leading to emails that appear incomplete or unprofessional. Poor Color Contrast: Bad color choices can make text hard to read, affecting the user experience. Unresponsive Design: Emails that are not optimized for mobile devices can appear cramped or difficult to navigate on smaller screens.