Summary
DKIM alignment confirms the signing domain matches the 'From' domain, crucial for DMARC compliance, while DKIM authentication verifies the signature's integrity. Failing DKIM, indicated by body hash errors or alignment issues, can lead to spam flagging, rejection, or bouncebacks. Hotmail blocks often stem from email content issues or poor IP reputation, especially with shared IPs on SFMC where the actions of other senders affect your deliverability. Maintaining good sending practices, verifying DKIM setup, monitoring IP reputation, and considering a dedicated IP are essential to mitigate these issues.
Key findings
- DKIM Verification: DKIM alignment ensures the signing domain matches the 'From' domain; authentication verifies signature integrity.
- Failure Consequences: DKIM failures, including body hash errors and alignment issues, can lead to spam flagging and rejections.
- Hotmail Blocking: Hotmail blocks are often related to email content or IP reputation, not SFMC itself.
- Shared IP Risks: Shared IPs on SFMC make you vulnerable to other senders' poor practices, impacting your deliverability.
- DMARC Importance: Proper DKIM alignment is vital for DMARC compliance, enhancing email security and deliverability.
Key considerations
- Maintain Sending Practices: Adhere to best practices to uphold a positive sending reputation and avoid IP-related blocks.
- Validate DKIM Setup: Regularly verify DKIM configuration to ensure correct alignment and authentication.
- Monitor IP Reputation: Keep a close watch on your IP's reputation to detect and address potential issues promptly.
- Consider Dedicated IP: If shared IP issues persist, explore switching to a dedicated IP for greater control over your reputation.
- Troubleshoot Bouncebacks: Investigate bounceback messages to pinpoint and resolve issues like authentication failures or content problems.
What email marketers say
13 marketer opinions
DKIM alignment ensures the domain signing the email matches the 'From' domain, while DKIM authentication verifies the signature's validity. Both are crucial for deliverability. Failing these checks, especially with strict DMARC policies, can lead to emails being flagged as spam, rejected, or bounced. Shared IPs, common in services like SFMC, can negatively impact deliverability because your sending reputation is tied to other users on the same IP. Poor sending practices by others can cause mailbox providers like Hotmail to block or filter emails, even if your DKIM is correctly configured. Maintaining a good IP reputation and monitoring sending practices are vital for avoiding bouncebacks and blocks.
Key opinions
- DKIM Alignment & Authentication: DKIM alignment and authentication are essential for verifying email legitimacy and preventing tampering.
- DMARC Dependence: Strict DMARC policies often require DKIM alignment; failure can result in rejection or spam filtering.
- Shared IP Risk: Shared IPs on platforms like SFMC can link your sending reputation to others, affecting deliverability.
- IP Reputation Impact: Poor IP reputation, influenced by other users on shared IPs, can lead to blocks and filtering by mailbox providers.
- Bounceback Causes: Bouncebacks can result from authentication failures, misconfigurations, or DNS issues.
Key considerations
- Monitor IP Reputation: Regularly monitor your IP reputation, especially when using shared IPs, to identify and address potential issues.
- Ensure DKIM Configuration: Verify that DKIM is properly configured and aligned to ensure email authenticity and prevent deliverability issues.
- Address Sending Practices: Adhere to email best practices to maintain a good sending reputation and avoid being impacted by other senders on shared IPs.
- Consider Dedicated IP: If deliverability issues persist with shared IPs, consider switching to a dedicated IP to have greater control over your sending reputation.
- Authentication Validation: Always make sure the Authentication passes, and domains match.
Marketer view
Email marketer from Validity notes that shared IPs can lead to deliverability issues if other senders on the IP have poor sending reputations. This is because mailbox providers often use IP reputation as a factor in determining whether to accept or reject emails. Senders using shared IPs must monitor their reputation closely.
27 Jun 2022 - Validity
Marketer view
Email marketer from Hubspot highlights that high bounce rates can be caused by authentication issues (such as DKIM failures) or a poor sending reputation. If your emails aren't properly authenticated, receiving servers are more likely to reject them, contributing to bouncebacks. Additionally, shared IP addresses might suffer from the actions of other senders using that IP.
30 Jul 2022 - HubSpot
What the experts say
8 expert opinions
DKIM alignment ensures the domain in the DKIM signature matches the 'From' domain, while DKIM authentication confirms the signature's validity. Failing body hash validation may indicate transient issues or problems with the email's content. MXToolbox DKIM verification may produce false negatives. Hotmail blocks are typically due to issues with the email content or the sending IP's reputation, not SFMC itself, and shared IPs can lead to deliverability problems if other users have poor sending practices. Correct DKIM alignment is also crucial for DMARC compliance. Helo command rejections from email services can also be a cause of bouncebacks from email providers.
Key opinions
- DKIM Definitions: DKIM alignment ensures domain matching, and authentication confirms signature validity.
- Validation Issues: Failing body hash validation may indicate temporary problems or content issues.
- MXToolbox Reliability: MXToolbox DKIM verification might have bugs, producing incorrect results.
- Hotmail Block Causes: Hotmail blocks are often linked to email content or IP reputation, not SFMC itself.
- Shared IP Risks: Shared IPs can cause deliverability issues due to the behavior of other users.
- DMARC Alignment: Proper DKIM alignment is essential for DMARC compliance.
- HELO command rejection: HELO command rejections can also cause deliverability issues.
Key considerations
- Verify DKIM Setup: Regularly verify DKIM configuration and troubleshoot any failures in signature or body hash validation.
- Alternative Verification: Use multiple DKIM verification tools to confirm results, given potential issues with MXToolbox.
- Content Scrutiny: Carefully review email content to prevent issues that may cause hash validation failures.
- Monitor IP Reputation: Monitor your sending IP's reputation and take steps to mitigate negative impacts from shared IP neighbors.
- DMARC Implementation: Ensure correct DKIM alignment to comply with DMARC policies.
- HELO Setup: Ensure the HELO setup is correct.
Expert view
Expert from Email Geeks explains that DKIM aligned means that the d= domain is aligned with the domain in the 5322.from address.
22 Nov 2023 - Email Geeks
Expert view
Expert from Word to the Wise explains that DKIM alignment means the domain used to sign the email (in the DKIM signature's 'd=' tag) matches the domain in the email's 'From:' header. This alignment is critical for DMARC compliance.
16 Jun 2024 - Word to the Wise
What the documentation says
3 technical articles
DKIM authentication uses digital signatures to verify the sender and ensure message integrity. DKIM alignment checks if the signing domain matches the 'From' domain, impacting spam filtering. Hotmail/Outlook.com blocks emails from shared IPs with poor reputations due to other senders' actions, emphasizing the need for best practices to maintain a good reputation and avoid blocks.
Key findings
- DKIM Authentication: DKIM provides a digital signature to verify the sender and message integrity.
- DKIM Alignment: DKIM alignment checks the match between the signing domain and the 'From' domain, affecting deliverability.
- Shared IP Reputation: Hotmail/Outlook.com blocks emails from shared IPs with poor reputations.
- Impact of Best Practices: Following best practices is crucial for maintaining a good sender reputation and avoiding blocks.
Key considerations
- Implement DKIM: Implement DKIM to digitally sign outgoing emails and improve deliverability.
- Ensure DKIM Alignment: Ensure DKIM alignment to prevent emails from being marked as spam.
- Monitor Reputation: Regularly monitor your sender reputation, especially on shared IPs.
- Follow Best Practices: Adhere to email sending best practices to maintain a good sender reputation and avoid blocks.
Technical article
Documentation from RFC Editor details the DKIM authentication process. It states that a DKIM signature allows a recipient to verify that the message was signed by a party authorized to use the domain in the 'd=' tag of the signature. Proper authentication ensures that the message content hasn't been altered during transit.
9 May 2023 - RFC Editor
Technical article
Documentation from Microsoft outlines that Hotmail/Outlook.com may block emails from senders using shared IPs if those IPs have a poor reputation due to the actions of other senders using the same IP. Senders need to follow best practices to maintain a good sending reputation and avoid being blocked.
25 Jun 2022 - Microsoft
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