There are several reasons why image rendering issues may occur. Common causes include: - Email Client Compatibility: Different email clients (e.g., Outlook, Gmail) have varying support for HTML and CSS, affecting how images are displayed. - Blocked Images: Some email clients block images by default to protect users from spam or phishing attempts. - Image Hosting: Slow or unreliable image hosting can lead to images not loading properly. - File Size and Format: Large image files or unsupported formats (like TIFF) can cause rendering problems.