Are HTTP links penalized by spam filters in email marketing?

Email marketer from Sendinblue explains that HTTPS links contribute to a safer user experience and can prevent browsers from flagging emails as potentially unsafe. They suggest that while it's not a direct spam trigger, it can impact user perception and engagement.

Email marketer from Email Geeks says using HTTP links stands out and should be highly discouraged.

Email marketer from Litmus explains that HTTPS links are essential for trust. While not a direct spam trigger, HTTP links can lead to warnings in email clients, impacting user engagement and sender reputation.

Email marketer from Quora answers that HTTP links can raise security concerns for users, leading to lower engagement rates. Even though direct spam filtering isn't always the case, user perception and trust are greatly affected, so HTTPS is preferable.

Email marketer from HubSpot shares HTTPS usage as a component of improving deliverability. While they don't specifically state HTTP links will be penalized, they advise using HTTPS to make your emails more secure and trustworthy.

Email marketer from Reddit mentions that using HTTP links might not trigger spam filters directly but can raise red flags with ISPs and email clients. Recommends using HTTPS to avoid potential deliverability issues.

Email marketer from Mailjet shares that while not a direct penalty, using HTTPS links improves trust and security, which can positively influence deliverability. They recommend using HTTPS to enhance sender reputation and avoid potential browser warnings.

Email marketer from StackOverflow shares that HTTP links, especially when redirecting, can trigger spam filters due to security concerns. They recommend using HTTPS for all links to ensure better deliverability.

Email marketer from Email on Acid suggests that while not a direct spam filter trigger, HTTP links in emails could degrade sender reputation over time. They advocate for HTTPS to maintain deliverability and credibility.

Expert from Spam Resource explains that the transition from HTTP to HTTPS is important for preventing mixed content warnings in email, which can erode trust in email marketing. Emails containing mixed content may get lower engagement.

Expert from Email Geeks shares a personal experience where using an HTTP Sendgrid redirector URL led to a “can’t connect securely” error in Mail.app.

Expert from Email Geeks states that Google search penalizes non-HTTPS pages and suggests Gmail might do the same.

Expert from Email Geeks advises avoiding HTTP links because it's been best practice for a long time. Links to helpful resources.

Expert from Email Geeks shares they have seen a non-zero shift in delivery for HTTP vs HTTPS and recommends moving to HTTPS.

Expert from Word to the Wise highlights the importance of upgrading to HTTPS, noting that webmail providers are now more likely to give preference to secure sites. They encourage marketers to switch to HTTPS as soon as possible because it's a ranking signal and it's important for security.

Documentation from Mozilla explains that browsers actively block mixed content (HTTP content on HTTPS pages) and suggests that delivering content solely over HTTPS is best practice for security and user experience. They also suggest this may result in a better open rate.

Documentation from RFC Editor recommends migrating entirely to HTTPS. While not explicitly penalizing HTTP links, the push toward secure connections means that HTTP can become outdated and affect user trust.

Documentation from IETF details the importance of using HTTPS. While the documentation doesn't explicitly mention a penalty for HTTP links in email marketing, it underlines the necessity of encryption and secure communication, which implies the importance of avoiding HTTP.

Documentation from Google Support explains that Gmail might display a warning if a message contains mixed content (both HTTP and HTTPS elements) and that while Gmail doesn't specifically penalize mixed content, it can affect user trust and perception, indirectly influencing engagement.

Documentation from NIST (National Institute of Standards and Technology) emphasises the importance of using current security protocols, like HTTPS. While it does not directly address email marketing, the information suggests that using HTTP, which is an older protocol, is generally discouraged in any online communication to reduce vulnerability.