Why are my DKIM and DMARC failing in Gmail, and how can I fix it?

Email marketer from Email Geeks explains DMARC failures occur when neither DKIM nor SPF are aligned, which is a common cause for emails landing in the spam folder. It is a sender issue where they should be looking at the headers.

Email marketer from Reddit shares that a common reason for DKIM/DMARC failure in Gmail is when you're using a third-party email service, and their DKIM signature or SPF record isn't properly set up to align with your domain. Contacting their support to ensure proper configuration is crucial.

Email marketer from Email on Acid explains that it is important to use testing tools to check your DKIM and DMARC records and also to check your email headers. This can help you see if the Authentication-Results: are passing or failing.

Email marketer from Mailjet explains that DMARC alignment failure happens when the domain in your 'From' address does not match the domain used for DKIM signing or SPF authentication. Ensuring these domains align is crucial for passing DMARC checks.

Email marketer from EasyDMARC shares that common reasons for DKIM failing include incorrect DNS configuration, modifications to the email content during transit, and using an outdated or incorrect DKIM key. They advise regularly checking your DKIM records and key rotation.

Email marketer from Sender Authentication Blog recommends double-checking your DNS records for typos or incorrect values. Even a small error in your SPF, DKIM, or DMARC record can cause authentication failures. Use online tools to validate your DNS records.

Email marketer from Postmark explains that DMARC policies (p=none, p=quarantine, p=reject) dictate how email receivers should handle messages that fail DMARC checks. Starting with 'p=none' allows you to monitor DMARC results without impacting deliverability, then transition to stricter policies as you gain confidence.

Email marketer from StackOverflow suggests checking your DMARC reports to identify the sources that are failing authentication. Often, these reports reveal misconfigured sending servers or unauthorized email sources using your domain. Adjust your SPF record and DKIM settings accordingly.

Email marketer from EmailGeekForum says that email forwarding can often break DKIM and SPF, leading to DMARC failures. If you're using email forwarding, consider alternative solutions like using a distribution list or having the original sender add your email address as a recipient.

Expert from Email Geeks explains that the DKIM failure might be a reporting choice by Google due to lack of alignment between the 'd=' in the DKIM signature and the 5322.from address, even if the DKIM signature itself passes cryptographic validation.

Expert from Word to the Wise answers that DMARC failures often stem from not having the DNS records configured correctly. Check your DNS zone file very carefully to make sure that your records are valid and fully propagated. Double check the records with a DNS lookup tool to ensure there are no typos and that it is returning what you expect.

Expert from Email Geeks mentions that the issue seems to be related to Gmail's 'you must align' directive from October 2023.

Expert from Spam Resource explains that a common cause of deliverability and authentication failures (SPF, DKIM, and DMARC) is mismatched forward and reverse DNS records. Ensure your sending server's IP address resolves to the correct hostname, and vice versa. This helps establish trust with receiving mail servers. There should also be a hostname.

Documentation from Microsoft Learn explains that if SPF is not configured correctly, it can cause DMARC to fail. Ensure that the SPF record includes all authorized sending sources for your domain and that the record is properly formatted to prevent authentication issues.

Documentation from dmarcian explains that DMARC failures typically occur when there is a mismatch between the domain used to sign the email (DKIM) or the sending IP address (SPF) and the domain in the 'From' address of the email. This lack of alignment causes DMARC to fail and can lead to deliverability issues.

Documentation from AWS explains how to verify your DKIM setup when using Amazon SES. Ensure that the DKIM DNS records provided by SES are correctly added to your domain's DNS settings. Incorrect or missing records will cause DKIM to fail.

Documentation from Google Workspace Admin Help explains that DKIM can fail if the key size is less than 1024 bits. They recommend generating a DKIM key that is 2048 bits for better security and to ensure compatibility with email providers like Gmail.