Summary
Gmail's flagging of internal emails as potentially dangerous is a multifaceted issue driven by machine learning, content analysis, and authentication protocols. Gmail uses machine learning to scan email content for phishing attempts or spam-like characteristics, which can inadvertently flag legitimate internal communications. Additionally, misconfigured authentication protocols like SPF, DKIM, and DMARC, even within the same domain, can lead to emails being marked as suspicious. Factors such as sender reputation, the use of URL shorteners, image-to-text ratios, and user reports contribute to this determination. The algorithms are constantly evolving, increasing the chances of misclassification. Implementing BIMI and ensuring well-formatted email headers can mitigate these risks. Consulting the mail audit log can provide additional insights. These alerts are also driven by ML models that produce "maybe" results, and feedback is used to help train the model, meaning that there is not a single cause.
Key findings
- Machine Learning-Driven: Gmail employs sophisticated machine learning algorithms that analyze various factors to identify potential threats.
- Content Similarity: Emails with content resembling phishing attempts or spam-like patterns are likely to be flagged.
- Authentication Protocols: Improperly configured SPF, DKIM, and DMARC settings, even within a domain, increase the risk of misclassification.
- Sender Reputation: A sender's reputation, influenced by user reports and engagement rates, affects deliverability.
- Multiple factors: There is not one single factor but the algorithms are considering many factors.
Key considerations
- Mail Audit Log Review: Examine mail audit logs to identify the specific reasons for Gmail's actions.
- Authentication Configuration: Ensure that SPF, DKIM, and DMARC are correctly configured for your domain, even for internal communications.
- BIMI Implementation: Consider implementing BIMI to establish brand trust and reduce the chance of emails being flagged.
- Content Assessment: Review email content for spam-like phrases or suspicious elements.
- Engagement Rate Monitoring: Monitor email engagement rates to maintain a positive sender reputation.
What email marketers say
12 marketer opinions
Gmail marks internal emails as potentially dangerous due to a variety of factors, including suspicious content resembling phishing attempts, authentication failures (SPF, DKIM, DMARC), sender reputation issues (low engagement, new/unused IP address), unusual email characteristics (image-to-text ratio, mismatched character sets), and overall content resembling spam. Gmail's machine learning models analyze various signals, and user feedback can also influence flagging decisions. Mail audit logs are useful to help determine why the email was marked dangerous.
Key opinions
- Content Analysis: Gmail scans email content for patterns resembling phishing attempts, spam-like phrases, or suspicious attachments and URLs.
- Authentication Issues: Failures in SPF, DKIM, and DMARC authentication can trigger Gmail's spam filters, even for internal emails.
- Sender Reputation: Low engagement rates, new or rarely used IP addresses, and sudden increases in email volume can negatively impact sender reputation and lead to flagging.
- Machine Learning: Gmail utilizes machine learning models that adapt based on various signals, including content, sender information, and user feedback.
- Email characteristics: High image-to-text ratios, mismatched character sets, and the use of URL shorteners can trigger spam filters.
Key considerations
- IT Audit: Consult your IT department and review mail audit logs to understand specific reasons for Gmail's actions.
- Authentication Setup: Ensure SPF, DKIM, and DMARC are properly configured for your domain, including internal systems.
- Content Review: Review email content for potentially problematic phrases, excessive use of exclamation points, and unusual formatting.
- Engagement Monitoring: Monitor email engagement rates (opens, clicks) and adjust sending practices to maintain a positive sender reputation.
- Filter learning: Ensure multiple recipients are not marking similar internal emails as spam
Marketer view
Email marketer from Quora shares that this usually happens if the email content closely matches phishing attempts, includes unusual URLs or attachments, or contains suspicious language.
15 Oct 2024 - Quora
Marketer view
Email marketer from Mailjet FAQ states that emails with unusually high image-to-text ratios or mismatched character sets can trigger spam filters.
4 May 2023 - Mailjet FAQ
What the experts say
3 expert opinions
Gmail may flag internal emails as potentially dangerous due to a variety of factors, including misconfigured email authentication (SPF, DKIM, DMARC), or content that resembles spam patterns. While it may not be a traditional spam filter issue, Gmail flags concerning content that could be a risk. The email's authentication settings need to be configured correctly, and care needs to be taken to avoid using phrases and formatting that is similar to that used in spam emails.
Key opinions
- Authentication Issues: Misconfigured SPF, DKIM, and DMARC, even within the same domain, can cause Gmail to flag internal emails.
- Content Analysis: Gmail's content filters can mistakenly identify internal emails as dangerous if they contain spam-like patterns.
- General Concern: Gmail might flag an email as concerning even if it's not strictly identified as spam.
Key considerations
- Authentication Setup: Ensure internal email systems have properly configured SPF, DKIM, and DMARC records.
- Content Review: Avoid using phrases, excessive punctuation, and formatting commonly found in spam emails.
- Root Cause: Even if the email isn't classified as spam, identify what triggered Gmail's warning message.
Expert view
Expert from Spam Resource shares that if internal emails contain content similar to known spam patterns (e.g., certain phrases, excessive use of exclamation points, or unusual formatting), Gmail's content filters might mistakenly flag them.
4 Dec 2023 - Spam Resource
Expert view
Expert from Word to the Wise explains that internal emails can be flagged due to misconfigured authentication (SPF, DKIM, DMARC) even within the same domain. Ensure internal systems are properly configured.
28 Nov 2024 - Word to the Wise
What the documentation says
5 technical articles
Gmail uses machine learning to identify spam and phishing attempts, considering factors like sender reputation, email content, and user reports. Improperly formatted email headers can lead to misinterpretation. Gmail's evolving algorithms, designed to detect new phishing tactics and malware distribution methods, may misclassify internal emails. Implementing DMARC and BIMI policies can improve deliverability and build brand trust, reducing the chances of emails being flagged.
Key findings
- Machine Learning: Gmail employs machine learning algorithms to identify spam and phishing.
- Header Formatting: Improperly formatted email headers can trigger misclassification.
- Algorithm Evolution: Gmail's algorithms continuously adapt to new threats, potentially leading to misclassification of internal emails.
- Sender Reputation: Sender reputation plays a role in the determination of whether an email is legitimate.
Key considerations
- DMARC Implementation: Implement a properly configured DMARC policy to improve deliverability.
- BIMI Implementation: Consider implementing BIMI to establish brand trust and reduce flagging.
- Header Validation: Validate email header formatting to ensure compliance with standards.
- Content Checks: Review email content for phishing triggers.
Technical article
Documentation from RFC Standard details that improper formatting of email headers can cause the algorithms of Google to misinterpret an e-mail as dangerous.
10 Sep 2022 - RFC-Editor
Technical article
Documentation from DMARC.org explains that a properly implemented DMARC policy can help improve deliverability and reduce the likelihood of Gmail flagging legitimate emails.
25 Dec 2021 - DMARC.org
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