1. Color Choices: Using colors that do not stand out from the email background or are not visually appealing can make buttons easy to overlook. It's crucial to use contrasting colors that draw attention to the CTA. 2. Size and Placement: Buttons that are too small or placed in hard-to-find locations can be easily missed. The button should be large enough to click comfortably and strategically placed where the user's eyes naturally go. 3. Unclear Messaging: Vague or overly complex CTA text can confuse recipients. The text on the button should be clear, concise, and action-oriented, such as "Buy Now" or "Learn More". 4. Lack of Mobile Optimization: With an increasing number of users checking emails on mobile devices, buttons must be responsive and easy to tap on small screens.