What does SSL_ERROR_BAD_CERT_DOMAIN mean for email links?

The SSL_ERROR_BAD_CERT_DOMAIN error specifically means the domain name in the SSL certificate does not match the website address you are trying to visit. For email click tracking, this typically occurs when the certificate on your custom tracking subdomain (e.g., links.yourdomain.com ) is either expired or issued for a different domain.

Who is responsible for the SSL certificate on my email click tracking domain?

In most cases, your email service provider (ESP) is responsible for provisioning and managing the SSL certificate for your custom click tracking domain, as they host the infrastructure that handles these clicks. However, it's crucial to confirm this with your ESP's support team, as some may require client involvement for domain verification or certificate provision.

Does this SSL error affect email deliverability or sender reputation?

Yes, indirectly. While it may not directly cause your emails to land in spam folders or your domain to be blocklisted, it significantly impacts user trust and click-through rates. Users who see security warnings are less likely to click your links, which can negatively affect your sender reputation over time due to low engagement signals. It can also cause a Hotmail SSL error .

What are the immediate steps to fix the SSL_ERROR_BAD_CERT_DOMAIN error?

Start by using an SSL checker tool to inspect your click tracking domain for expired certificates or name mismatches. Then, contact your ESP's support team immediately. Provide them with the exact error message and your click tracking domain. They should be able to diagnose and rectify the certificate issue on their end.

How can I prevent this error from happening again in the future?

Regularly monitor the validity of your SSL certificates using online tools. Ensure clear communication with your ESP about their SSL certificate management process for your custom tracking domains. Proactive monitoring and timely renewal are key to preventing these errors.

How do I fix SSL_ERROR_BAD_CERT_DOMAIN error for my email click tracking domain? - Technical - Email deliverability - Knowledge base

Encountering the SSL_ERROR_BAD_CERT_DOMAIN error for your email click tracking domain can be a frustrating experience. It typically means that when someone clicks a link in your email, their browser displays a security warning, often stating a potential security risk ahead and preventing them from accessing the intended content. This issue directly impacts your email campaign's effectiveness and user trust.

At its core, this error indicates a problem with the SSL certificate associated with your click tracking domain. This domain, often a subdomain like links.yourcompany.com, is what your email service provider (ESP) uses to redirect clicks and gather analytics. When the certificate on this domain is either expired or doesn't match the actual domain name, browsers throw up red flags.

Addressing this error is crucial not just for deliverability, but also for maintaining a positive user experience and protecting your brand's reputation. Ignoring it can lead to frustrated recipients and ultimately, lower engagement with your email campaigns.

Understanding the SSL_ERROR_BAD_CERT_DOMAIN error

The SSL_ERROR_BAD_CERT_DOMAIN error message indicates a fundamental problem: the browser attempting to load the link sees an SSL certificate that does not match the domain name it expects. This mismatch is a critical security alert, as it prevents the browser from verifying the authenticity of the website. For example, Mozilla Support specifically highlights this as a name mismatch issue, signaling that the certificate presented belongs to a different domain.

In the context of email click tracking, this error commonly arises from a few scenarios. Firstly, the SSL certificate provisioned for your tracking domain (e.g., clicks.yourdomain.com) might have been issued for an entirely different domain, or it could be a generic certificate from your ESP that doesn't include your specific tracking subdomain. Secondly, the certificate might simply be expired. If the renewal process was overlooked, the certificate becomes invalid, leading to these warnings. A third, less common but impactful, scenario involves typographical errors or misconfigurations in your DNS settings that point to the wrong certificate.

When users encounter these errors, their immediate reaction is often to abandon the link. This directly translates to reduced click-through rates and, over time, can impact your sender reputation, as ISPs might perceive low engagement as a sign of irrelevant or unwanted emails.

Who owns the SSL certificate for your click tracking domain?

A common point of confusion when dealing with SSL_ERROR_BAD_CERT_DOMAIN errors on click tracking domains is determining who is responsible for the SSL certificate. When you set up a custom click tracking domain (e.g., track.yourdomain.com), you typically create a CNAME record that points to your ESP's infrastructure. This means that while the domain is yours, the server hosting the click tracking functionality belongs to your ESP.

In most cases, your ESP is responsible for provisioning and managing the SSL certificate for this specific click tracking subdomain. They control the servers where the CNAME points, and thus, they are typically the ones to install and renew the SSL certificate. However, some ESPs might have specific requirements, such as asking you to provide the certificate or perform a domain verification step on your end. It is recommended to configure SSL or TLS on your sending domains.

The quickest way to resolve this ownership mystery is to contact your ESP's support team. They can clarify their exact process for SSL certificate management on custom tracking domains, confirm if they've provisioned the correct certificate, and initiate any necessary fixes. This direct communication is vital, as attempting to install a certificate yourself on a domain hosted by your ESP could lead to further complications.

Troubleshooting and resolving the issue

Once you understand the potential causes, troubleshooting the SSL_ERROR_BAD_CERT_DOMAIN error involves a systematic approach. Start by confirming the exact error you're seeing in the browser, specifically looking for messages about name mismatches or expired certificates. A good first step is to use an SSL checker tool to inspect your click tracking domain. This will tell you if the certificate is expired, or if it has been issued for a different domain.

Key checks for your click tracking domain

Verify domain: Ensure the domain used for click tracking matches the SSL certificate's common name or Subject Alternative Name (SAN).
Check expiration: Confirm the SSL certificate for your tracking domain is not expired.
Consult ESP: Contact your email service provider to discuss their SSL handling for click tracking domains.

Expired certificate

An expired SSL certificate is one of the most straightforward causes. If the certificate's validity period has passed, browsers will no longer trust it, leading to the SSL_ERROR_BAD_CERT_DOMAIN error. This usually requires renewal and re-installation, a process typically managed by your ESP if they host the tracking domain.

Domain mismatch

A domain mismatch occurs when the SSL certificate is issued for a domain different from your click tracking domain. This could happen if a generic certificate is used or if there's a legacy certificate from a previous brand or configuration. Fixing this involves obtaining and installing a new certificate that precisely matches your click tracking subdomain.

Example CNAME record for click trackingDNS

links.yourdomain.com. CNAME track.esp.com.

Another factor to consider is HSTS (HTTP Strict Transport Security). If your primary domain or a parent domain has HSTS enabled, browsers might automatically attempt to access any subdomains using HTTPS. If your click tracking domain isn't properly secured with an SSL certificate, this forced HTTPS connection will fail, triggering the error. Discuss with your ESP whether they can support SSL on your tracking domains (CNAMEs), or if a reroute through a domain host that supports SSL is needed. This ensures that HTTP/HTTPS protocol discrepancies do not impact your email deliverability.

Impact on email performance and reputation

While an SSL error on your click tracking domain might not directly lead to your sending domain being placed on a blocklist or blacklist, it severely impacts user experience and email engagement metrics. When recipients encounter security warnings after clicking a link, they are highly unlikely to proceed to the destination page. This leads to a significant drop in click-through rates (CTR).

Over time, consistent low engagement due to broken or untrusted links can indirectly affect your sender reputation. Internet Service Providers (ISPs) monitor engagement signals. If users consistently do not click your links, or worse, mark your emails as spam because of a poor experience, it can signal to ISPs that your emails are not valuable or trustworthy. This can contribute to your emails landing in the spam folder rather than the inbox, even if your main sending domain (or sending domain differing) is otherwise well-configured.

Ensuring a seamless and secure click experience is vital for your email program's success. A valid SSL certificate on your click tracking domain builds trust with your recipients and provides a smooth journey from email to landing page. This contributes positively to your overall sender reputation and ensures your messages continue to reach the inbox, avoiding potential spam folder issues.

Views from the trenches

Best practices

Ensure all custom email tracking domains have valid, up-to-date SSL certificates.

Regularly check certificate expiration dates to prevent service interruptions for users.

Confirm the certificate's common name or SAN precisely matches your tracking domain.

Engage your ESP's support team to verify their process for managing tracking domain SSL.

Common pitfalls

Ignoring security warnings from browsers can severely impact user trust and engagement.

Assuming your ESP automatically handles SSL for all custom tracking domains without verification.

Not renewing SSL certificates on time, leading to expired certificates and errors.

Misconfiguring DNS records, causing certificate mismatches or invalid lookups.

Expert tips

Leverage an SSL checker tool to proactively identify any issues with your tracking domain.

Understand the interplay between HSTS and SSL to prevent forced HTTPS errors.

Document the ownership and renewal process for all custom domains within your organization.

Prioritize a seamless user experience by maintaining valid SSL across all email links.

Marketer view

Marketer from Email Geeks says they found their link tracking domain had two SSL certificates, one expired with a name mismatch for an old brand, and another correct one.

October 7, 2022 - Email Geeks

Expert view

Expert from Email Geeks says that if an ESP domain lacks SSL setup, and an HTTPS link attempts connection, a default certificate appears.

October 7, 2022 - Email Geeks

Ensuring secure email links for better deliverability

The SSL_ERROR_BAD_CERT_DOMAIN error for your email click tracking domain is a critical issue that compromises both user trust and the effectiveness of your email marketing efforts. It's a clear signal that the security of your links is compromised, leading to a frustrating experience for your recipients and potential abandonment of your calls to action.

To effectively address this, the key lies in understanding that your ESP typically manages the SSL certificate for your click tracking domain. Close communication with their support team is essential to ensure that the certificate is correctly provisioned, remains valid, and accurately matches your tracking domain.

By actively monitoring and resolving these SSL issues, you secure your email infrastructure, maintain a positive user experience, and ultimately contribute to stronger email deliverability and improved campaign performance. A seamless click experience is not just a technical detail, but a cornerstone of successful email engagement.