It is a common question whether your website's SSL/TLS configuration directly impacts your email deliverability. On the surface, it might seem like these two aspects of online security are intertwined, given that both involve encryption protocols. However, the connection is not as direct as some might assume.
Website SSL/TLS primarily secures the connection between a user's browser and your website, enabling HTTPS. This ensures data privacy and integrity for web traffic. Email deliverability, on the other hand, relies on a different set of protocols and factors, including email-specific TLS for transport encryption, alongside robust email authentication records like SPF, DKIM, and DMARC.
Indirect impact on sender reputation
While website SSL/TLS doesn't directly influence your email server's ability to send emails or how often they land in the inbox, there's an important indirect relationship through sender reputation and recipient trust. Modern email providers and spam filters are increasingly sophisticated, evaluating not just the email itself but also the overall digital footprint of the sending domain.
If emails contain links to a website, and that website lacks a valid SSL/TLS certificate, or if it has an expired or self-signed certificate, it can raise red flags. Recipients might see security warnings in their browsers, leading to a loss of trust. This negative user experience can, over time, indirectly affect your brand's overall reputation, which some advanced spam filters might consider when determining inbox placement.
Moreover, search engines like Google prioritize websites with HTTPS. A secure website contributes to a stronger online presence and a perception of legitimacy. While this is primarily an SEO factor, a domain perceived as untrustworthy in one area could implicitly affect how it is viewed in others, including email. Ensuring secure HTTPS links within your emails is also a key deliverability best practice.
Understanding email TLS encryption
It is critical to distinguish between website SSL/TLS and email TLS. While both protocols serve to encrypt data, they operate at different layers and for different purposes. Website SSL/TLS encrypts data between a web server and a browser, while email TLS encrypts the communication path between mail servers (and between mail clients and servers). DigiCert explains these are distinct.
For email, the use of TLS encryption is highly important for deliverability. It protects the privacy and integrity of your emails as they travel across the internet. Without it, messages are sent in plain text, making them vulnerable to interception and tampering. Major email providers, including Gmail, prefer or even require TLS for incoming mail. Failing to use it can lead to messages being rejected, delayed, or flagged as suspicious. This is why you should configure TLS on your sending domains for email marketing.
Configuring TLS for your email server usually involves ensuring that your SMTP service is set up to use opportunistic TLS, or enforcing it where possible. This is distinct from installing an SSL certificate on your web server. Modern TLS versions (like TLS 1.2 or 1.3) are also preferred, as older versions are being deprecated due to security vulnerabilities.
SMTP TLS Commandplaintext
STARTTLS
SMTP commands for initiating a secure TLS connection.
Many email service providers (ESPs) handle the underlying TLS configuration for email sending, but if you manage your own mail servers, it's crucial to ensure proper setup. Pronto Marketing highlights the importance of security on both fronts.
Website SSL/TLS and email links
Website SSL/TLS
Secures data between a web browser and your website. Primarily affects search engine rankings and user trust in your web presence.
Ensures visitors see a secure connection (HTTPS) rather than a warning about an unsecured site.
Indirectly influences email deliverability by affecting user perception when clicking links within emails, and potentially impacting broader domain reputation if your website is perceived as insecure.
Email TLS
Encrypts email messages during transit between mail servers. Directly impacts email security and deliverability.
Ensures privacy of email content and prevents eavesdropping or tampering during transmission. This is especially important for sensitive communications.
Directly influences whether emails are accepted by recipient servers. Absence or outdated versions of email TLS can lead to emails being rejected or sent to spam.
While a broken or non-existent website SSL/TLS doesn't immediately cause emails from that domain to land in spam, it contributes to a general lack of trust. Mailforge underscores the importance of SSL validation. If your emails include links to an insecure website, recipients might be deterred from clicking, or spam filters might flag the content due to the associated risk. This is particularly relevant for marketing emails where engagement is key. For cold email campaigns, ensuring that tracking domains use SSL is a critical step in maintaining deliverability. Elastic Email emphasizes this point.
It is also worth noting that if you use an email service provider, they typically handle the TLS encryption for the email transport itself. However, ensuring your landing pages and linked content are secure with a valid SSL certificate is still vital. This protects the recipient's experience once they click on a link in your email and contributes to a perception of credibility. For more information on securing tracked links, explore the importance of SSL for tracked links and images.
Warning: Bad certificates in email links
Links within your email body that point to websites with expired, self-signed, or otherwise invalid SSL/TLS certificates can negatively impact your email deliverability. Mailbox providers (ISPs) often scan linked content, and encountering security warnings on your linked pages can trigger spam filters, pushing your emails to the junk folder. Always ensure all links within your emails point to secure (HTTPS) URLs with valid certificates. This is a common pitfall that can harm sender reputation and lead to blacklisting (or blocklisting) issues.
Views from the trenches
Best practices
Always ensure your website (and any linked landing pages) has a valid, up-to-date SSL/TLS certificate to maintain user trust and avoid browser warnings.
Verify that your email service provider or mail server is configured to use the latest versions of TLS for email transmission to secure your messages in transit.
Regularly check your DMARC, SPF, and DKIM records to ensure proper email authentication, which is far more direct to email deliverability.
Monitor your domain's reputation with mailbox providers to proactively address any potential issues related to security or content.
Common pitfalls
Ignoring website SSL/TLS warnings because they 'don't directly affect email' can lead to an erosion of overall domain trust.
Including links in emails to pages with expired or self-signed SSL certificates, which can trigger spam filters and reduce inbox placement.
Neglecting email-specific TLS configuration on self-managed mail servers, leading to insecure email transmission and potential delivery failures.
Failing to implement or properly configure email authentication protocols like DMARC, SPF, and DKIM, which are crucial for deliverability.
Expert tips
Use a consistent and secure domain for all email activities, including links and tracking, to build a strong, unified sender reputation.
Educate your marketing and web teams on the importance of comprehensive domain security, bridging the gap between website and email practices.
Implement DMARC reporting to gain visibility into email authentication failures, including potential issues related to linked content being flagged.
While not directly related to email, a secure website enhances your brand's legitimacy, which can indirectly contribute to positive perceptions by mailbox providers.
Marketer view
Marketer from Email Geeks says that having a website with broken or non-existent TLS/SSL does not directly affect the email deliverability of emails from that domain. The two security aspects operate independently.
2020-06-20 - Email Geeks
Expert view
Expert from Email Geeks says that while website TLS doesn't directly impact email deliverability, Google's move to include email TLS in their transparency report suggests a potential future correlation similar to how DKIM evolved into a filtering factor.
2020-06-20 - Email Geeks
The holistic view of domain security
While a website's SSL/TLS doesn't directly control whether your emails land in the inbox, it plays a vital role in your brand's overall digital security posture and user trust. A secure website, indicated by HTTPS, contributes to a positive perception of your domain. Conversely, a website with security flaws, especially broken SSL/TLS, can indirectly harm your email deliverability by eroding recipient trust and flagging suspicion for advanced spam filters that analyze linked content.
For optimal email deliverability, prioritize both email-specific TLS encryption and robust email authentication (SPF, DKIM, DMARC). Additionally, ensure that any links within your emails lead to secure, HTTPS-enabled websites with valid SSL certificates. This comprehensive approach builds a strong sender reputation and helps ensure your messages reach their intended recipients.
