Summary
While one expert claims images don't impact deliverability, the consensus is that images indirectly affect it. Large, unoptimized images slow loading times, leading to poor user experience and increased spam flagging. Proper image optimization (compression, format), balanced text-to-image ratio, alt text, and reputable hosting are essential for good deliverability. Poor design, including excessive or poorly-optimized images, can also negatively impact deliverability. Documentation from Google, Microsoft, and HubSpot stresses the importance of image optimization.
Key findings
- Image Size & Loading: Large image sizes increase loading times, negatively affecting user experience and engagement.
- Optimization is Key: Optimizing images (compression, format, alt text) is crucial for deliverability and accessibility.
- Text-to-Image Balance: Maintaining a healthy text-to-image ratio helps prevent spam flagging.
- Hosting Matters: Using reputable image hosting (CDNs, ESPs) is important for deliverability.
- Design Affects Deliverability: Poorly designed emails, especially with unoptimized images, increase spam risk.
- Image Blocking Impact: Image blocking impacts rendering, therefore alt text is important.
Key considerations
- Compress Images: Reduce image file sizes to improve loading times and deliverability.
- Choose Proper Format: Use appropriate file formats (JPEG for photos, PNG for graphics) to optimize image quality and size.
- Add Alt Text: Include descriptive alt text for accessibility and context when images are blocked.
- Balance Text and Images: Ensure a healthy text-to-image ratio to avoid spam filters.
- Select Reputable Hosting: Use reliable image hosting services to prevent deliverability issues.
- Design for Deliverability: Design emails with deliverability in mind, avoiding excessive or poorly optimized images.
- Check rendering with image blocking: Check that an email still makes sense when images are blocked so that if images fail to load it still makes sense and gets your message accross.
What email marketers say
11 marketer opinions
While images themselves may not directly cause deliverability issues, their size, optimization, and usage significantly impact email deliverability. Large image file sizes increase loading times, which can lead to lower engagement and potential spam filtering. Image blocking by email clients can also affect how messages are displayed. Therefore, optimizing images through compression, proper formatting (JPEG/PNG), and the inclusion of alt text is crucial. Maintaining a healthy text-to-image ratio and hosting images on reputable servers further contributes to improved deliverability.
Key opinions
- Image Size Matters: Large image file sizes can slow loading times, negatively impacting engagement and potentially leading to emails being flagged as spam.
- Optimization is Crucial: Compressing images, using appropriate file formats (JPEG/PNG), and adding alt text are essential for optimizing images for email.
- Text-to-Image Ratio: Maintaining a balanced text-to-image ratio is important; too few text with many images can trigger spam filters.
- Image Hosting: Hosting images on reputable servers or CDNs is crucial, as poor hosting can lead to blacklisting and affect deliverability.
- Image Blocking: Image blocking affects display, so alt text usage to provide context where images dont render is an important consideration
Key considerations
- Optimize Image Sizes: Reduce image file sizes to minimize loading times and improve user experience.
- Use Appropriate File Formats: Select the correct file format (JPEG for photos, PNG for graphics) to optimize image quality and size.
- Include Alt Text: Add descriptive alt text to images to provide context when images are blocked or fail to load.
- Balance Text and Images: Ensure a healthy text-to-image ratio to avoid triggering spam filters.
- Reputable Hosting: Host images on reliable servers or CDNs to prevent deliverability issues.
- Check rendering with image blocking: Check that an email still makes sense when images are blocked so that if images fail to load it still makes sense and gets your message accross.
Marketer view
Email marketer on an Email Marketing Forum mentions that hosting images on a reputable server is important as poor image hosting can indirectly affect deliverability if the server is blacklisted. They recommend using reliable CDNs or ESPs for image hosting.
16 Jan 2023 - Email Marketing Forum
Marketer view
Email marketer on Quora says an imbalance between text and images, especially with too little text, can flag emails as spam. It's important to maintain a healthy text-to-image ratio.
2 Aug 2022 - Quora
What the experts say
3 expert opinions
The impact of images on email deliverability is nuanced. One expert states that images do not impact deliverability. However, other experts suggest that while images themselves are not directly flagged as spam, excessive or large images and poorly designed emails with unoptimized images can negatively affect deliverability. Optimization and maintaining a balanced text-to-image ratio are recommended.
Key opinions
- Conflicting Views: Opinions vary on whether images directly impact deliverability.
- Optimization Matters: Large, unoptimized images can contribute to deliverability issues by slowing down loading times and potentially triggering spam filters.
- Design Impacts: Poorly designed emails with unbalanced text-to-image ratios can be flagged as spam.
Key considerations
- Optimize Images: Ensure images are optimized for web use to reduce file size and loading times.
- Balance Text and Images: Maintain a healthy text-to-image ratio to avoid triggering spam filters.
- Consider Email Design: Design emails with deliverability in mind, ensuring that images are not excessive or poorly placed.
Expert view
Expert from Word to the Wise explains that poorly designed emails can be flagged as spam, including emails with large images that have not been optimised which slow loading times. Laura recommends optimising images and balancing them with enough text.
25 Oct 2021 - Word to the Wise
Expert view
Expert from Spam Resource explains that while images themselves aren't directly flagged as spam, using excessive or large images can negatively impact deliverability. They recommend optimizing images and maintaining a good text-to-image ratio.
22 Aug 2023 - Spam Resource
What the documentation says
4 technical articles
Documentation from Google, Microsoft, Mozilla, and HubSpot highlights the importance of image optimization for email deliverability and user experience. Large images can contribute to emails being flagged as spam and can negatively affect loading times, which in turn can harm subscriber engagement. Using alt text for accessibility and following image guidelines for optimal viewing are also crucial.
Key findings
- Large Images = Spam Risk: Large image file sizes can increase the likelihood of emails being flagged as spam by Gmail.
- Image Optimization Improves UX: Optimizing images reduces loading times, improving the overall subscriber experience.
- Alt Text Enhances Accessibility: Using alt text for images ensures accessibility for users who cannot see them, and improves the experience if images fail to load.
- Adherence to Guidelines: Following image guidelines ensures optimal viewing in email clients and prevents rendering issues.
Key considerations
- Compress Images: Reduce image file sizes through compression to improve loading times and deliverability.
- Size Images Appropriately: Ensure images are appropriately sized for email viewing to avoid rendering issues.
- Use Alt Text: Always include descriptive alt text for images to provide context and accessibility.
- Follow Image Guidelines: Adhere to image guidelines and best practices to ensure optimal viewing in various email clients.
Technical article
Documentation from HubSpot Support advises on best practices for improving email deliverability, including image optimisation. They emphasize reducing image file sizes, as large images can lead to longer loading times and a poor subscriber experience, both of which can negatively affect deliverability.
23 May 2022 - HubSpot
Technical article
Documentation from Mozilla Developer Network emphasizes the importance of alt text for images to provide accessibility for users who can't see them, and to ensure a usable experience if images are not loading. While not directly about deliverability, using alt text is a best practice for accessible emails.
17 Aug 2022 - Mozilla Developer Network
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