Outdated Browser or App Using an outdated web browser or outdated version of the Yahoo Mail app can lead to compatibility issues. These compatibility issues can prevent certain functions, such as deleting emails, from working correctly. It’s essential to keep your browser or app up to date to ensure smooth performance. Browser Cache and Cookie Accumulated cache and cookies in your browser can interfere with the proper functioning of Yahoo Mail. These temporary files may cause conflicts, making it difficult to delete emails. Clearing your browser’s cache and cookies can help resolve this issue. Technical Glitche