Why is MXToolbox showing email authentication errors when ESP says everything passes and how to fix bot unsubscribes?

Email marketer from Mailjet shares that a DMARC policy of 'reject' or 'quarantine' can cause MXToolbox to flag issues if SPF or DKIM checks fail, even if the ESP reports successful delivery to some recipients. They advises monitoring DMARC reports to identify authentication failures and adjust SPF/DKIM settings or DMARC policy accordingly.

Email marketer from Superuser explains that the ESP might be whitelisting your domain and this is the reason why the results are different. For example, the DMARC policy will be ignored if you are whitelisted. This explains the differences in email authentication results.

Email marketer from WordtotheWise explains that the MXToolbox check is a snapshot in time and does not run constantly. The report may have been taken when a server was down or having other issues. This report may now be old data and inaccurate.

Email marketer from Stackoverflow suggests the difference in SPF/DKIM/DMARC results between MXToolbox and ESPs are because MXToolbox is running its tests from a different location and therefore gets a different result from DNS. It is also possible that some firewalls are causing MXToolbox to time out and therefore report a failure.

Email marketer from Litmus shares that MXToolbox checks may not accurately reflect real-world deliverability. MXToolbox results should be seen as a starting point and not an end-all-be-all. Email authentication is complex and MXToolbox should be used in combination with other tools.

Email marketer from Sendinblue shares that bot unsubscribes are often due to bots clicking unsubscribe links in emails. They recommends implementing a double opt-in process for subscriptions, using CAPTCHAs on unsubscribe pages, and monitoring unsubscribe rates for suspicious patterns to mitigate the issue.

Email marketer from Neil Patel explains that discrepancies between MXToolbox and an ESP can arise from DNS propagation delays, MXToolbox's outdated information, or the ESP's use of dedicated IPs with different authentication settings than the domain's overall DNS records. He suggests verifying DNS settings with multiple tools and allowing sufficient time for propagation.

Email marketer from Reddit says that including a confirmation page after clicking the unsubscribe link is the most common solution to prevent bot unsubscribes. This page confirms the intention to unsubscribe to filter bot requests.

Email marketer from EmailonAcid responds that because email authentication setups are unique and have varying configurations, MXToolbox can sometimes provide inaccurate results or false positives. Always view MXToolbox results alongside other testing and deliverability analysis.

Expert from Email Geeks explains that MXToolbox is generally reliable but the issues reported sound like either messed up DNS or DNSSEC problems.

Expert from Spamresource explains that often times the results differ due to the timing. MXToolbox can provide results based on its last check. It recommends using other tools such as the ESP as they are more reliable.

Expert from Email Geeks explains the best practice is that the link in the email should take the user to a web page where they click a button to unsubscribe. Requiring only a single click unsub from the email is not a good practice and results in bot unsubscribes. Implementing a web page with a button will fix the bot issue.

Expert from Email Geeks shares their analysis of the email headers and DNS records. They believe the issue is that MXToolbox isn't handling SPF macros correctly and is checking the domain in the 5322.from for DMARC, which doesn't have a record itself, but the parent domain does. Since DKIM aligns, the email is likely passing authentication. Overall, Laura thinks it's a reporting problem, not a configuration problem.

Expert from WordtotheWise explains that one-click unsubscribe options can be exploited by bots, leading to unintentional unsubscriptions. Providing users with a confirmation page and a CAPTCHA before fully processing the unsubscribe can prevent bot unsubscribes.

Expert from WordtotheWise recommends that senders should ensure that they are compliant with all major types of authentication. This includes SPF, DKIM and DMARC. This helps improve sender reputation and reduces the risk of ending up in the junk folder.

Documentation from DigitalOcean suggests one solution to bot attacks is implementing a 'honeypot field'. This is a hidden form field that bots will fill out but humans will not see. If the honeypot field is filled, the request is discarded.

Documentation from Microsoft Learn explains DKIM failures even when the ESP reports success may result from key rotation issues (new keys not properly propagated), incorrect selector settings in DNS, or DNS caching problems. The documentation suggests checking the DKIM key validity, selector configuration, and DNS records using diagnostic tools.

Documentation from Sparkpost explains what the exists mechanism is used for when configuring your SPF. Exists confirms that the domain name exists, and the test passes if the domain name exists. Sparkpost uses the exists macro when authenticating emails and is not the same as just having an include.

Documentation from DMARC.org describes what DMARC is and what it is designed for. DMARC is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing.

Documentation from RFC 8058 describes that a one-click unsubscribe can be abused by malicious actors as they can use bots that automatically unsubscribe users without their consent. It recommends using a 'List-Unsubscribe-Post' header in your emails, it allows recipients to unsubscribe using a POST request instead of a GET request which is what malicious bots use. You should use a unsubscribe link that leads to a webpage where the user can confirm their unsubscribe action.

Documentation from Google Workspace Admin Help explains that SPF errors in MXToolbox, despite ESP reports, may stem from SPF record syntax errors, exceeding the 10 DNS lookup limit, or incorrect 'include:' statements. The documentation advises using SPF record validation tools to identify and correct errors.