When you delve into the world of email authentication, you often come across various tags and parameters within DNS records like DKIM. These tags are crucial for ensuring your emails are delivered safely and are not mistaken for spam or phishing attempts. Among these, the 'g' tag in a DKIM record is one that sometimes causes confusion, especially as its role has evolved over time.
Understanding each component of your email authentication setup is vital for maintaining a strong sender reputation and achieving optimal email deliverability. While some tags remain central to DKIM's function, others, like the 'g' tag, have become less relevant or have even been deprecated. Let's explore what the 'g' tag once represented and its current status in DKIM records.
The 'g' tag: an historical overview
The 'g' tag, or 'granularity' tag, was originally designed to offer a finer level of control over the identity that a public key was permitted to sign for within a domain. Its purpose was to specify the "local part" of an email address, which is the segment before the '@' symbol. For instance, if you had an 'i=' tag of sender@example.com, a 'g=' tag could be used to restrict the public key's authority to only sign for that specific local part, sender.
However, this level of granularity proved to be complex and largely unused in practical implementations. Over time, the email ecosystem evolved, and the need for such specific control at the local part level diminished. The overhead of managing separate keys or policies for individual local parts wasn't justified by its benefits.
Deprecation in RFC 6376
The 'g' tag was officially deprecated in RFC 6376, the updated standard for DomainKeys Identified Mail (DKIM). This means that modern DKIM implementations and verifiers no longer expect or use this tag. Its removal streamlined the DKIM specification, focusing on the tags that are truly essential for email authentication.
While you might still encounter references to the 'g' tag in older documentation or discussions, it's important to recognize that it is no longer a functional part of a DKIM record. Focusing on currently relevant tags will ensure your DKIM setup is effective and compliant with contemporary email security standards.
Decoding DKIM records and tags
A DKIM record is a DNS TXT record that contains the public key used to verify the authenticity of emails sent from your domain. Beyond the public key itself, a DKIM record utilizes various tags to convey essential information to receiving mail servers. These tags enable proper verification and play a significant role in determining an email's legitimacy.
Example DKIM recordDNS
selector1._domainkey.yourdomain.com. IN TXT "v=DKIM1; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDgkgKxS1Yw7f5Kz/wQ; s=email; t=s; h=sha256; c=relaxed/simple;"
While the 'g' tag is no longer in use, many other DKIM tags are critical for successful email authentication. These tags provide instructions to receiving mail servers about how to process the DKIM signature. Some specify the domain signing the email, others detail the algorithm used, and some even indicate the expiration time of the signature.
Tag
Description
Current Status
v=
Version of DKIM record, always 'DKIM1'.
Required
p=
The public key used for verification. If empty, it revokes the domain's signing ability.
Required
s=
The selector name which points to the specific DKIM key.
The identity (usually an email address) that signed the email, if different from the "From" header. This is the agent or user responsible.
Optional
q=
The query method used to retrieve the public key, typically 'dns/txt'.
Optional, defaults to 'dns/txt'
Each of these tags contributes to the overall security posture of your email. Misconfigurations or outdated information can lead to authentication failures, resulting in your emails being marked as spam or (blocklisted) blacklisted, significantly impacting your deliverability.
Why understanding DKIM tags matters for deliverability
Ensuring your DKIM records are correctly configured and up-to-date is paramount for email deliverability. DKIM works alongside SPF and DMARC to form a robust email authentication framework. Without proper DKIM implementation, even legitimate emails can fail authentication checks, making them susceptible to spoofing and phishing attacks.
A valid DKIM signature allows receiving mail servers to confirm that an email was indeed sent by the domain it claims to be from and that it hasn't been tampered with in transit. This trust is essential for avoiding spam folders and protecting your domain reputation. Incorrectly configured DKIM can lead to a host of problems, including bounces and emails being marked as suspicious.
Incorrect DKIM configuration
Increased spam rate: Emails are more likely to land in recipients' spam folders.
Domain reputation damage: Your domain might be perceived as a source of untrustworthy emails.
Phishing and spoofing risk: Malicious actors can more easily send emails pretending to be from your domain.
DMARC failures: Inaccurate DKIM can cause your DMARC policy to fail, impacting enforcement.
Correct DKIM configuration
Improved inbox placement: Emails are more likely to reach the primary inbox.
Stronger domain reputation: Builds trust with email service providers and recipients.
Enhanced security: Protects your brand from email impersonation and abuse.
Moreover, ensuring your DKIM records are valid helps in mitigating DKIM body hash mismatch failures and avoids common DKIM TempError issues that can disrupt your email flow. Regular checks and monitoring are key.
Monitoring and managing your DKIM records
Given the dynamic nature of email security protocols and the constant threat of phishing, actively monitoring your DKIM records is essential. While the 'g' tag is no longer relevant, staying informed about current best practices and the functionality of other DKIM tags is crucial for maintaining effective email authentication.
Tools that provide comprehensive DMARC monitoring are invaluable for this. They allow you to see how your emails are performing, identify authentication failures, and pinpoint issues with your DKIM (and SPF) setup. This proactive approach helps you quickly address problems before they impact your email deliverability or domain reputation.
Effortless DKIM and DMARC management with Suped
Suped provides an intuitive platform for monitoring your email authentication, including DKIM. Our AI-powered recommendations help you fix issues and strengthen your policy, making complex DMARC data actionable. With real-time alerts and a unified platform for DMARC, SPF, and DKIM monitoring, you can ensure your emails are always authenticated correctly. Explore our generous free plan to start protecting your domain today.
Regularly reviewing your DMARC reports, which rely on DKIM authentication results, will give you clear insights into any potential authentication failures. This allows you to quickly adapt and optimize your email sending practices, ensuring robust protection against email fraud and consistently high deliverability rates.
Ensuring your email authentication is up to date
The 'g' tag in a DKIM record is a relic of an earlier version of the DKIM specification, having been deprecated due to its complexity and limited practical use. While it once offered a fine-grained control over local part identity, modern email authentication focuses on the active and essential DKIM tags that reliably verify email authenticity.
Staying current with DKIM standards and actively monitoring your email authentication is paramount for protecting your brand and ensuring your emails reach their intended recipients. By understanding the relevant DKIM tags and leveraging effective monitoring tools, you can fortify your email security and achieve superior deliverability.
AI-powered recommendations help you fix issues and strengthen your policy, making complex DMARC data actionable. With real-time alerts and a unified platform for DMARC, SPF, and DKIM monitoring, you can ensure your emails are always authenticated correctly. Explore our generous free plan to start protecting your domain today.
