Why is DKIM alignment with the 5322.from domain important for email authentication?
Summary
What email marketers say10Marketer opinions
Marketer from Email Geeks refers to a Wikipedia article and RFC, explaining that DKIM signatures should include the 'From' field. They link to the Wikipedia article: <https://en.wikipedia.org/wiki/DomainKeys_Identified_Mail#:~:text=%5Bedit%5D-,Signing,-%5Bedit%5D> and RFC documentation: <https://datatracker.ietf.org/doc/html/rfc6376#section-5.4>
Email marketer from Reddit suggests that DKIM and SPF need to be correctly configured and aligned with DMARC policies to avoid emails being marked as spam. Alignment issues often stem from mismatches between the 'From' domain and the DKIM signing domain.
Email marketer from Postmarkapp.com explains that DKIM alignment improves email deliverability by verifying the sender's identity. When the DKIM signature aligns with the 'From' domain, it signals to email providers that the email is legitimate.
Email marketer from MailerLite.com shares that DKIM alignment helps build trust with email providers and recipients. Aligned DKIM records show that the sender is taking steps to verify their identity, reducing the risk of spam complaints and improving email engagement.
Email marketer from MessageBird.com (previously SparkPost) explains that DKIM alignment builds sender reputation. When the DKIM 'd=' domain aligns with the 'From' domain, ISPs are more likely to trust the sender, improving inbox placement.
Email marketer from Sendinblue.com explains that achieving DMARC compliance requires DKIM alignment. This ensures that the 'From' address is genuinely associated with the sending domain and that the correct digital signature is in place.
Email marketer from EasyDMARC.com shares that if DKIM is not aligned, it can cause a DMARC failure, leading to emails being rejected or sent to spam. Alignment confirms the sender's identity and prevents domain spoofing.
Email marketer from Mailjet.com answers that DKIM alignment, in conjunction with DMARC, provides a robust authentication framework. It helps prevent spoofing by validating that the sender is authorized to send emails on behalf of the domain, and if it fails the receiver knows what to do with the email.
Email marketer from Valimail.com shares that DMARC alignment is crucial for DKIM to pass DMARC checks. It ensures that the domain in the DKIM signature (d=) matches the domain in the From: header. This alignment verifies the sender's authorization to use the domain.
Email marketer from EmailAuthForum explains that both SPF and DKIM must be configured correctly, and properly aligned with DMARC to gain the full benefits of email authentication.
What the experts say4Expert opinions
Expert from Spam Resource explains that DKIM alignment is crucial for DMARC to work effectively. It validates the sender's identity and ensures that the email is not spoofed, enhancing email authentication.
Expert from Word to the Wise shares that proper email authentication, including DKIM alignment, is a key factor in achieving good email deliverability and avoiding the spam folder. Alignment helps build trust with mailbox providers.
Expert from Email Geeks explains that aligned hostnames in DMARC don't need to be identical, but share an organizational domain, giving the example that `d=aardvark.example.com` is aligned with `From: bob@blueberry.example.com`.
Expert from Email Geeks clarifies the problem is about having a valid DKIM signature with a 'd=' value aligned with the domain in the 5322.from field. She also points to resources regarding Microsoft's implicit authentication: <https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/email-authentication-about?view=o365-worldwide#composite-authentication>, <https://support.clickdimensions.com/hc/en-us/articles/360042239312-Implicit-Authentication-for-Microsoft-Outlook-Exchange-O365->, <https://knowledge.validity.com/hc/en-us/articles/360040763112-What-is-Microsoft-s-anti-spoofing-protection-change-and-how-does-it-impact-me->, and <https://techcommunity.microsoft.com/t5/security-compliance-and-identity/schooling-a-sea-of-phish-part-2-enhanced-anti-spoofing/ba-p/176209>.
What the documentation says5Technical articles
Documentation from Cloudflare.com explains that DKIM alignment improves email security by making it harder for attackers to spoof legitimate email addresses. Properly aligned DKIM signatures provide assurance that the email truly originated from the claimed domain.
Documentation from support.google.com explains that Gmail requires DKIM alignment for bulk senders to ensure messages are properly authenticated. This protects Gmail users from spam and phishing.
Documentation from Microsoft.com explains composite authentication in Microsoft 365 relies on DKIM alignment. If DKIM aligns, it strengthens the authentication signal, reducing the chance of the email being marked as spam.
Documentation from ietf.org explains that the 'From' header field must be signed (included in the "h=" tag) in the DKIM-Signature header field. This ensures the message's claimed author is verified.
Documentation from AuthSMTP mentions that DKIM alignment helps ensure that the 'header from' domain, matches the 'd' domain in the DKIM signature. This validates the integrity of the email.