Summary
The Gmail message 'Images in this email are hidden' appears when Gmail suspects spam or the sender's reputation is low, or because of user or Google Workspace administrator settings. It reduces engagement, click-through rates, and conversions by preventing images from displaying. Image proxy usage by Gmail also affects open tracking accuracy. To mitigate this, marketers should focus on improving sender reputation via SPF, DKIM, and DMARC, optimizing images (compression, format, alt text), using responsive design, providing plain text versions, and balancing layout with clear text and background colors. A/B testing and awareness of user privacy settings are also crucial.
Key findings
- Causes for Image Blocking: Low sender reputation, spam suspicion, user settings, and Google Workspace admin settings trigger image blocking.
- Impact on Email Marketing: Hidden images reduce engagement, click-through rates, conversions, and affect open tracking accuracy due to image proxies.
- Sender Reputation Importance: A good sender reputation is vital for ensuring images are displayed, involving authentication, list hygiene, and avoiding spam triggers.
- Image Optimization Techniques: Optimizing images with compression, proper formats, and descriptive alt text ensures a better experience even when images are blocked.
- Design Strategies: Using responsive design, balanced layouts, background colors, bulletproof buttons, and plain text versions help maintain engagement when images don't load.
- Privacy and Security: Image blocking protects users from tracking and malicious content.
Key considerations
- Prioritize Sender Reputation: Implement SPF, DKIM, and DMARC; maintain clean lists; and avoid spam triggers to improve sender reputation.
- Optimize Images: Compress images, use appropriate formats (JPEG, PNG), and add descriptive alt text for accessibility.
- Design for Image Blocking: Employ responsive design, balanced layouts, and background colors to ensure emails are effective even without images.
- Offer Plain Text Alternative: Include a plain text version of the email to ensure content is accessible when images are blocked.
- User Settings Awareness: Be mindful that user settings in Gmail impact image display and tracking.
- Image Proxy Impact: Understand how Gmail's image proxy skews open tracking metrics.
- A/B Test Approaches: Experiment with different strategies to find what resonates best with your audience, particularly on mobile devices.
What email marketers say
10 marketer opinions
The Gmail message 'Images in this email are hidden' can appear for several reasons, including low sender reputation, suspicion of spam, or user/administrator settings. This negatively impacts email marketing by reducing engagement, click-through rates, and conversions. To mitigate these effects, marketers should focus on improving sender reputation through email authentication (SPF, DKIM, DMARC), maintaining clean email lists, and avoiding spam triggers. They should also optimize images by compressing them, using appropriate formats, and adding descriptive alt text. Designing emails that look good with or without images, using responsive design principles, and providing a plain text version are also recommended. A/B testing different approaches is beneficial to determine what resonates best with the audience.
Key opinions
- Causes: The 'Images are hidden' message may appear due to low sender reputation, spam suspicion, or Google Workspace admin settings.
- Impact: Hidden images negatively affect open rates, click-through rates, user experience, and overall conversions.
- Mitigation: Improving sender reputation and optimizing images can help prevent image blocking and improve email performance.
- Design: Designing emails to be effective with or without images is crucial for maintaining engagement.
- Testing: A/B testing different email strategies helps determine what resonates best with the audience.
Key considerations
- Sender Reputation: Prioritize building and maintaining a positive sender reputation through authentication, list hygiene, and avoiding spam triggers.
- Image Optimization: Optimize images by compressing them, using appropriate formats (JPEG, PNG), and adding descriptive alt text for accessibility and context.
- Responsive Design: Use responsive design principles to ensure emails render correctly on different devices and in various email clients, even with images blocked.
- Plain Text Version: Include a plain text version of the email to ensure recipients can still access the content if images are blocked.
- Image proxies: Be aware that services such as Gmail use image proxies, which can affect open tracking.
- Fallback design: Ensure you have fallback designs and/or background colours to compensate for images being blocked.
Marketer view
Email marketer from Email on Acid explains that image blocking in Gmail can lead to broken or missing content, which can damage the user experience and reduce conversions. Marketers should use responsive design principles to ensure their emails look good with or without images, optimize alt text for accessibility, and test their emails in different email clients to understand how they render with images blocked.
7 Sep 2023 - Email on Acid Blog
Marketer view
Email marketer from HubSpot Blog explains that designing emails that look good with or without images involves using a balanced layout with clear text, strategic use of background colors, and ensuring that key information is conveyed through text as well as images. Responsive design principles should be applied to ensure the email renders correctly on different devices and in various email clients, even with images blocked. Also use bulletproof buttons using HTML and VML.
26 Sep 2022 - HubSpot Blog
What the experts say
5 expert opinions
The Gmail message 'Images in this email are hidden' suggests Gmail suspects the email is potentially spam but lacks the confidence to directly filter it. This is influenced by factors like sender reputation and new ESP pairings. It particularly affects emails with low reputation, causing image blocking. A more aggressive stance against cold outreach platforms contributes to this. Gmail employs image proxies, impacting open tracking accuracy as pixels are triggered by Google's servers, not the recipient. Image blocking serves as a privacy feature, preventing automatic image downloads and mitigating tracking and malicious content loading, reducing marketer tracking capabilities.
Key opinions
- Spam Suspicion: Gmail's 'Images hidden' message signals a spam suspicion without outright filtering, influenced by sender reputation and ESP pairings.
- Low Reputation Impact: Emails with low reputation are more likely to have images blocked, impacting deliverability.
- Cold Outreach Blocking: Google increasingly blocks images in cold outreach emails, reflecting a stricter stance on spam.
- Image Proxy Impact: Gmail's image proxy skews open tracking metrics by triggering pixels through Google's servers, not the recipient.
- Privacy Protection: Image blocking serves as a privacy feature, preventing tracking and malicious content loading.
Key considerations
- Sender Reputation: Monitor and improve sender reputation to minimize spam suspicion and image blocking.
- Email Source: If sending cold outreach, be aware of Google's increasing vigilance towards this type of email.
- Tracking Limitations: Account for the impact of image proxies on open tracking metrics and adjust analytics accordingly.
- Privacy Considerations: Understand image blocking as a privacy feature and adjust marketing strategies to respect user privacy preferences.
- ESP Pairing: Consider that new pairings between your ESP and email address may affect deliverability.
Expert view
Expert from Word to the Wise explains that image blocking in Gmail (and other email clients) is a privacy feature that prevents the automatic downloading of external images. This protects users from being tracked via tracking pixels and prevents the loading of potentially malicious content. Users must explicitly click to display images, giving them control over what content is loaded. This reduces a marketers ability to track opens.
22 Jul 2023 - Word to the Wise
Expert view
Expert from Email Geeks shares that the message about hidden images has been appearing for about a month and seems to affect emails with low reputation, causing images not to display.
30 Nov 2021 - Email Geeks
What the documentation says
4 technical articles
Gmail's 'Images in this email are hidden' message relates to user-controlled image display settings, where Gmail may block images by default for suspicious emails or if users choose to enhance privacy. Gmail uses an image proxy that caches images, impacting open tracking accuracy by pre-fetching images and potentially inflating open rates. Implementing SPF, DKIM, and DMARC improves sender reputation, increasing the likelihood of Gmail displaying images. Providing descriptive alt text is essential for accessibility when images are blocked, ensuring users still understand the email's purpose.
Key findings
- User Control: Gmail allows users to control image display settings, impacting when images are automatically shown.
- Image Proxy: Gmail utilizes an image proxy for caching images, which can skew open tracking metrics.
- Authentication: SPF, DKIM, and DMARC authentication standards enhance sender reputation and image display likelihood.
- Accessibility: Descriptive alt text is crucial for providing context and accessibility when images are blocked.
Key considerations
- Privacy Settings: Be aware of user privacy settings in Gmail that can affect image display and tracking.
- Tracking Accuracy: Understand the impact of Gmail's image proxy on open tracking metrics and adjust campaign analysis accordingly.
- Email Authentication: Implement SPF, DKIM, and DMARC to improve sender reputation and increase the chances of image display.
- Alt Text Importance: Always include descriptive alt text for images to ensure accessibility and convey the message when images are blocked.
Technical article
Documentation from RFC explains that SPF, DKIM, and DMARC are email authentication standards that help verify the sender's identity and prevent email spoofing. Implementing these standards can improve sender reputation and ensure that Gmail is more likely to display images, as it trusts authenticated senders more than unauthenticated ones.
4 Feb 2022 - RFC Editor
Technical article
Documentation from Litmus explains that Gmail uses an image proxy to cache images, which can affect open tracking. The proxy pre-fetches images, potentially inflating open rates because an email can be counted as opened even if the recipient doesn't view it. Marketers need to be aware of this discrepancy when analyzing email campaign performance and use metrics beyond open rates to gauge engagement.
26 Sep 2023 - Litmus
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