What causes Gmail DKIM domain rate limiting errors and how are they related to SPF?

Email marketer from Sendinblue explains that SPF, DKIM, and DMARC are email authentication protocols that help improve email deliverability and protect your domain from spoofing and phishing attacks. Implementing these protocols can reduce the likelihood of your emails being marked as spam and improve your sender reputation.

Marketer from Email Geeks reports receiving the same transient DKIM error with DKIM [ 15].

Marketer from Email Geeks shares an error message they encountered: `421-4.7.28 Gmail has detected an unusual rate of unsolicited mail originating from your DKIM domain [ 15].` They mention it's not a help request but a PSA.

Email marketer from Reddit shares that Gmail's rate limiting can occur when SPF or DKIM fail consistently. If Gmail detects that a significant portion of your emails are failing authentication checks, it may temporarily limit the sending rate from your domain to protect its users from spam and phishing attacks.

Email marketer from Litmus emphasizes the importance of maintaining a clean email list to improve deliverability and avoid rate limiting. Regularly removing inactive subscribers, addressing hard bounces, and segmenting your list based on engagement can help to reduce spam complaints and improve your sender reputation.

Email marketer from DNSQueries explains that being on a email blacklist can cause rate limits. You should regularly check your domain/IP address against known email blacklists. This can tell you if your email has been detected as spam and is causing rate limiting.

Marketer from Email Geeks explains that after looking into the DKIM issue, the limit is mild, and few senders are affected. They suspect it could be a reaction to an aligned domain or a bug.

Email marketer from Stack Overflow explains that SPF hard fails (indicated by "-all") can cause deliverability issues, especially if legitimate emails are being sent from IPs not included in your SPF record. Gmail may be more likely to rate limit domains with strict SPF policies that result in a high number of authentication failures.

Email marketer from GlockApps explains that a poor sender reputation can significantly impact your email deliverability and potentially lead to rate limiting. Factors that contribute to a poor sender reputation include high bounce rates, spam complaints, and authentication failures. Monitoring your sender reputation and taking steps to improve it is crucial for avoiding deliverability issues.

Email marketer from Email On Acid shares that DNS issues, such as incorrect or outdated SPF and DKIM records, can lead to authentication failures and potentially trigger Gmail's rate limiting. Regularly monitoring your DNS records and ensuring they are correctly configured is crucial for maintaining email deliverability.

Marketer from Email Geeks shares they also encountered an error with the SPF being marked as spammy. After blocking the SPF sender, the DKIM bounces stopped, suggesting a connection between the two.

Email marketer from UltraTools shares to perform an SPF record lookup. This allows you to determine if your DNS records are correctly configured. You should run this if you suspect that the SPF setup is not correct. You can also look up other peoples SPF records to see if they have the same errors as you.

Email marketer from Mailjet shares that SPF and DKIM are essential for email authentication. SPF helps prevent spoofing by verifying that the sending server is authorized to send emails on behalf of your domain. DKIM adds a digital signature to your emails, which helps verify that the email hasn't been tampered with during transit. When properly configured, they enhance deliverability and protect your domain's reputation.

Email marketer from Neil Patel explains that improving your sender reputation by authenticating your emails with SPF, DKIM, and DMARC can help to avoid spam filters. Also that keeping your email lists clean and only sending to engaged users. He also suggests avoiding spam trigger words and maintaining a consistent sending volume.

Marketer from Email Geeks confirms they are also seeing the SPF error, reinforcing Sergey's observation.

Expert from Word to the Wise explains that DMARC needs both SPF and DKIM, however DMARC only cares about the domain in the From: header. The alignment mode tells the receiver if the SPF and DKIM results need to match.

Expert from Spam Resource explains that SPF is used to show which servers are permitted to send mail from a domain. If a server sends from a domain but isn't listed as permitted in the SPF, then this should be treated as spam. He also explains that it does not break forwarding.

Expert from Word to the Wise shares that DKIM is often seen as more complex to implement but offers advantages in terms of handling forwarded emails and situations where SPF might fail. If a message is forwarded, DKIM signatures should remain valid, as the message content and headers are typically preserved, whereas SPF can fail if the forwarding server isn't authorized in the original domain's SPF record.

Documentation from Google Workspace Admin Help explains that to prevent Gmail from limiting your DKIM domain, ensure you are following bulk email senders guidelines, specifically related to authentication, spam rates, and clear unsubscribe options. They also suggest monitoring your sender reputation using Postmaster Tools.

Documentation from RFC 7489 (DMARC standard) explains that DMARC builds upon SPF and DKIM by providing a policy that specifies how email receivers should handle messages that fail SPF and DKIM checks. DMARC allows domain owners to instruct receivers to reject, quarantine, or deliver emails that fail authentication, providing an additional layer of protection against email spoofing.

Documentation from dmarc.org explains that SPF and DKIM are complementary authentication methods. SPF verifies the sending server's IP address, while DKIM verifies the message's integrity and authenticity. They work together to establish trust and improve email deliverability. If SPF fails but DKIM passes, the email may still be delivered.

Documentation from AuthSMTP explains the need to check your DKIM record. Check if you have any errors by using a third party tool. Common record errors are caused by extra spaces, too long, incorrect selector in the query or multiple DKIM records.

Documentation from Microsoft shares some information about bulk sender guidelines. They mention that poor list hygiene, high complaint rates, and authentication issues can lead to deliverability problems and potential rate limiting. Microsoft says it's important to follow best practices for email sending to avoid being flagged as a spammer.