What happens if an image is blocked by a spam filter?

Spam filters can block specific images while allowing the email through. This uisn't the same as client-side image blocking. The filter identifies the image URL or content as suspicious and strips it from the message or replaces it with a warning.

Triggers for image blocking: Suspicious hosting domain (known spam image hosts). URL reputation (domains associated with spam). Content fingerprinting (image hash matches known spam images). Malware signatures (images carrying payloads).

Host images on reputable infrastructure. Use your own domain, a major CDN, or your ESP's image hosting. Avoid free image hosts or domains with questionable reputation. If filters block your images, investigate the hosting source-the URL reputation may be the problem, not the image itself.