Summary
Using HTTPS for links and images in email marketing is crucial for several reasons encompassing security, deliverability, user experience, and future compatibility. HTTPS ensures data encryption, protecting sensitive information and building user trust. Many email clients are implementing stricter security policies, potentially blocking or warning users about non-HTTPS content. HTTPS helps prevent man-in-the-middle attacks and ensures data integrity. It also resolves rendering issues, especially in 'view online' versions and dark mode, providing a more seamless experience across devices and applications. The use of HTTPS avoids mixed content warnings and potential blocking by browsers. While it doesn't directly impact website SEO, using HTTPS links indirectly improves brand perception. Issues such as HSTS and browser warnings further reinforce the need for HTTPS to ensure consistent functionality and security, making it a best practice for future-proofing email marketing strategies. Google's preference for HTTPS might also benefit deliverability, particularly to Gmail users. Moreover, HTTPS enables the use of HTTP/2, which can potentially improve website loading speed and overall user experience.
Key findings
- Enhanced Security: HTTPS encrypts data, preventing interception and ensuring privacy, thus building user trust and safeguarding sensitive information.
- Improved Deliverability: Email providers are increasingly likely to flag or block emails with HTTP links, making HTTPS essential for maintaining good deliverability and avoiding spam filters.
- Better User Experience: HTTPS resolves rendering issues, especially in 'view online' versions and dark mode, and provides a more seamless experience across devices, avoiding mixed content warnings.
- Future-Proofing: Adopting HTTPS is a proactive measure as browsers and email clients become stricter on security, ensuring consistent functionality and compatibility in the long run.
- HSTS Prevention: Using HTTPS prevents the HTTP Strict Transport Security (HSTS) from causing HTTP links that redirect to HTTPS sites to fail until the browser cache is cleared.
- Performance Improvement: HTTPS enables HTTP/2, potentially improving website loading speed and overall user experience if links point to secure websites.
Key considerations
- Enforce HTTPS Everywhere: Ensure all links and images in your emails use HTTPS to provide a secure and reliable experience for recipients.
- Test Across Platforms: Thoroughly test emails in various email clients and browsers, particularly when 'view online' versions are used, to avoid mixed content and rendering issues.
- Update Existing Campaigns: Review and update existing email templates and campaigns to replace HTTP links with HTTPS equivalents.
- Educate Your Audience: Inform your audience about the security benefits of HTTPS and the steps you're taking to protect their data to build trust and encourage engagement.
- Check Image Rendering: Verify images render correctly, especially in dark mode email clients, which might have different default settings for displaying HTTP images.
- Monitor Security Policies: Stay informed about evolving email client and browser security policies to ensure your emails remain compliant and functional.
What email marketers say
12 marketer opinions
Using HTTPS for links and images in email marketing is crucial for several reasons. It ensures data encryption, protecting sensitive information and building user trust. Many email clients are implementing stricter security policies, potentially blocking or warning users about non-HTTPS content. HTTPS helps prevent man-in-the-middle attacks and ensures data integrity. It also improves rendering, particularly in 'view online' versions and dark mode, while providing a more seamless experience across devices. While it does have a direct impact on website SEO, using HTTPS links indirectly improves brand perception. Additionally, issues like HSTS and browser warnings reinforce the need for HTTPS to ensure consistent functionality and security, making it a best practice for future-proofing email marketing strategies.
Key opinions
- Security: HTTPS encrypts data, preventing interception and ensuring privacy, which enhances user trust and safeguards sensitive information.
- Deliverability: Email providers are increasingly likely to flag or block emails with HTTP links, making HTTPS essential for maintaining good deliverability.
- Rendering Issues: Mixing HTTP and HTTPS content can cause rendering problems in email clients, especially in 'view online' versions and dark mode, leading to broken images or warnings.
- HSTS Complications: HTTP Strict Transport Security (HSTS) can cause issues where HTTP links redirecting to HTTPS sites will fail until cache is cleared.
- Future Proofing: Adopting HTTPS is a proactive measure as browsers and email clients become stricter on security, ensuring consistent functionality in the long run.
Key considerations
- Enforce HTTPS: Ensure all links and images in your emails use HTTPS to provide a secure and reliable experience for recipients.
- Test Rendering: Thoroughly test emails in various email clients and browsers, particularly when 'view online' versions are used, to avoid mixed content rendering issues.
- Update Links: Review and update existing email templates and campaigns to replace HTTP links with HTTPS equivalents.
- Educate Users: Inform your audience about the security benefits of HTTPS and the steps you're taking to protect their data to build trust and encourage engagement.
- Dark Mode Rendering: Ensure HTTPS is used when sending emails so users using dark mode email clients can view the images and they render correctly.
Marketer view
Email marketer from Email Geeks explains that images in emails must be HTTPS, or they may not load in some email clients like Comcast when accessed over HTTPS. Chrome may auto-upgrade HTTP images to HTTPS if available. Gmail uses a proxy so this is not an issue.
13 Jan 2022 - Email Geeks
Marketer view
Email marketer from Litmus Community responds that using HTTP images can lead to rendering issues in some email clients, especially when the email itself is viewed over HTTPS. This can result in broken images or security warnings.
17 Nov 2022 - Litmus Community
What the experts say
3 expert opinions
Using HTTPS for links and images in email marketing is important for several reasons. Browsers are increasingly warning about non-HTTPS links, and eventually emails might not display correctly. Google favors HTTPS links, potentially improving email deliverability to Gmail users. More broadly, HTTPS builds user trust by ensuring a secure, encrypted connection, protecting sensitive information and preventing eavesdropping and man-in-the-middle attacks.
Key opinions
- Browser Warnings: Browsers are beginning to display warnings for HTTP links, indicating a move towards requiring HTTPS for all web content.
- Future Compatibility: Emails using only HTTP may eventually not display correctly in some clients.
- Google Favoritism: Google favors HTTPS, which may give emails with HTTPS links an advantage, especially for Gmail users.
- User Trust: HTTPS builds trust by encrypting the connection between the user and the server.
- Security: HTTPS protects sensitive information by preventing eavesdropping and man-in-the-middle attacks.
Key considerations
- Transition to HTTPS: Make a plan to transition all email links and images to HTTPS to ensure compatibility and security.
- Update Existing Emails: Update any existing email templates and campaigns to use HTTPS links and images.
- Monitor Browser Warnings: Stay informed about browser updates and security changes that might affect how emails with HTTP content are displayed.
- Prioritize Security: Understand the security implications of using HTTP and educate your team on the importance of HTTPS.
- Consider Gmail Optimization: Keep Google's preference for HTTPS in mind when designing your email marketing strategy.
Expert view
Expert from Email Geeks explains that while HTTP links might work for a while, browsers are increasingly warning about non-HTTPS links, and eventually, emails might not display correctly without HTTPS.
25 Nov 2023 - Email Geeks
Expert view
Expert from Email Geeks shares that Google favors HTTPS links in search rankings and that there is a likely benefit to using HTTPS in emails to Gmail.
26 Oct 2024 - Email Geeks
What the documentation says
4 technical articles
Using HTTPS for links and images in email marketing is important because it addresses multiple security and performance concerns. Mixed content (HTTPS pages loading HTTP resources) weakens security, leading browsers to block content or display warnings, thus impacting user experience. HTTPS protects data integrity by preventing attackers from tampering with transmitted data, ensuring recipients see the intended content. Additionally, HTTPS helps prevent man-in-the-middle attacks through encryption, safeguarding user data. Using HTTPS also enables the use of HTTP/2, which can improve website loading speed via header compression, multiplexing, and server push, enhancing overall user experience.
Key findings
- Mixed Content Security Risk: Mixed content (HTTPS loading HTTP resources) weakens overall security, leading to browser warnings or content blocking.
- Data Integrity: HTTPS protects data integrity, preventing attackers from altering transmitted information.
- Man-in-the-Middle Prevention: HTTPS prevents man-in-the-middle attacks by encrypting the communication channel.
- Performance Enhancement: HTTPS enables HTTP/2, improving website loading speed and user experience.
Key considerations
- Avoid Mixed Content: Ensure that all resources loaded on HTTPS pages, including those linked from emails, are also served over HTTPS to avoid security warnings and blocking.
- Prioritize Data Integrity: Implement HTTPS to guarantee the integrity of transmitted data, preventing unauthorized modifications.
- Secure Communication Channels: Use HTTPS to encrypt communication channels and prevent man-in-the-middle attacks, protecting sensitive information.
- Optimize Website Performance: Enable HTTP/2 to improve website loading speed and overall user experience, ensuring a faster and more efficient connection.
Technical article
Documentation from Mozilla Developer Network explains HTTPS protects data integrity, preventing attackers from tampering with resources transmitted over the network. This is crucial for ensuring email recipients see the intended content.
16 Sep 2022 - Mozilla Developer Network
Technical article
Documentation from DigiCert explains that HTTPS helps prevent man-in-the-middle attacks by encrypting the communication channel. This protects user data and ensures that attackers cannot intercept or modify the email content or linked resources.
14 Mar 2025 - DigiCert
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