Summary
Outbound TLS is considered essential for secure email marketing. It encrypts email traffic during transit, protecting sensitive data and preventing interception and data breaches. It also demonstrates a commitment to security, building trust with recipients and positively impacting sender reputation and deliverability. Failing to implement TLS can lead to warnings from email providers like Gmail. GDPR and similar regulations may also mandate TLS for email security. Implementation should extend beyond the email body to include CTA URLs and other resources. Opportunistic TLS is an option, but not as effective as requiring TLS connections. It is a standard practice, the lack of which can raise red flags.
Key findings
- Encryption: TLS encrypts email traffic, preventing unauthorized access to sensitive information during transit.
- Reputation & Trust: Implementing TLS builds trust with recipients and improves sender reputation, enhancing deliverability.
- Regulatory Compliance: TLS helps comply with data protection regulations like GDPR, which mandate security measures for personal data.
- Industry Standard: TLS is considered an industry-standard security practice for email communication.
- Gmail Warnings: Gmail displays warnings on messages without TLS, negatively impacting user perception.
Key considerations
- Scope of TLS: TLS should be implemented not only for email content but also for CTAs and other embedded resources.
- Enforced vs. Opportunistic: While Opportunistic TLS is better than none, requiring TLS connections provides superior security by preventing fallback to plain text.
- OpenSSL: OpenSSL can assist with enabling TLS and ensure you are up to date with the latest versions.
What email marketers say
11 marketer opinions
Outbound TLS is considered essential for modern email marketing. It encrypts email traffic in transit, protecting sensitive data from interception and data breaches. It is also a demonstration of commitment to security and builds trust with recipients, positively impacting sender reputation and deliverability. GDPR may also require TLS for email security. Implementation should extend beyond the main email content to include CTA URLs and other remote resources. It encrypts email traffic from sending to receiving server, preventing content sniffing. Without TLS, SMTP transactions expose sensitive data in plain text.
Key opinions
- Encryption: TLS encrypts email traffic during transit, preventing eavesdropping and protecting sensitive information.
- Trust & Reputation: Implementing TLS builds trust with recipients and enhances sender reputation, which can improve deliverability.
- Security Compliance: GDPR and other regulations may require TLS to ensure the security of personal data transmitted via email.
- Best Practice: TLS is now considered a standard best practice, and its absence can raise suspicion.
Key considerations
- Scope of Implementation: TLS should be implemented not only for email content but also for CTA URLs and any other remote resources (images, CSS, etc.)
- Opportunistic vs. Enforced: Opportunistic TLS is better than nothing but isn't as secure as enforced TLS as it falls back to plain text if the receiving server doesn't support TLS. If possible enforce TLS.
Marketer view
Marketer from Email Geeks states outbound TLS shouldn't even be optional anymore.
9 Jun 2023 - Email Geeks
Marketer view
Marketer from Email Geeks advises that TLS should also be implemented for CTA URLs and any other remote resources like CSS and images.
15 Mar 2024 - Email Geeks
What the experts say
4 expert opinions
Experts emphasize the necessity of outbound TLS for email marketing due to the secure channel it provides, protecting sensitive information from interception and contributing to sender reputation. A lack of TLS can result in warnings from email providers like Gmail. Opportunistic TLS is a potential solution, but falls back to plain text if TLS isn't supported by the receiving server.
Key opinions
- TLS is Essential: Outbound TLS is considered absolutely necessary for secure email communication.
- Gmail Warnings: Gmail displays warnings for messages sent without TLS, which can negatively impact recipient trust.
- Reputation Boost: Using TLS demonstrates a commitment to security, contributing positively to sender reputation.
- Data Integrity: TLS helps maintain the integrity of email data during transmission.
Key considerations
- Opportunistic TLS Limitations: While Opportunistic TLS is better than nothing, it's not ideal as it defaults to plain text if the receiving server doesn't support TLS.
Expert view
Expert from Email Geeks states that outbound TLS is absolutely necessary.
4 Nov 2023 - Email Geeks
Expert view
Expert from Wordtothewise.com explains that TLS provides a secure channel for email communication, protecting sensitive information from interception. It contributes to sender reputation by demonstrating a commitment to security and helps maintain data integrity.
28 Mar 2024 - Wordtothewise.com
What the documentation says
4 technical articles
Technical documentation indicates that TLS provides communications privacy and data integrity through encryption. It secures SMTP mail flow, protecting communications with trusted partners. TLS can be implemented in various environments, like Java, to protect web communications. OpenSSL offers resources to implement different TLS versions.
Key findings
- Privacy and Integrity: TLS secures communications by providing both privacy and data integrity.
- Secure Mail Flow: Enabling TLS secures SMTP mail flow, especially with trusted business partners.
- Versatile Implementation: TLS can be implemented in a variety of environments, including Java applications and web communications.
- Version Support: OpenSSL provides documentation on supported TLS versions and their implementation.
Key considerations
Technical article
Documentation from Microsoft Learn explains that enabling TLS for SMTP helps secure mail flow between your Microsoft 365 or Office 365 organization and your trusted business partners. It's a way to encrypt email communications.
10 Nov 2023 - Microsoft Learn
Technical article
Documentation from RFC5246 explains that The Transport Layer Security (TLS) Protocol provides communications privacy and data integrity. The protocol is composed of two layers: the TLS Record Protocol and the TLS Handshake Protocol.
16 May 2022 - RFC5246
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