Summary
Intentionally delivering emails to the spam folder can be achieved through a combination of technical misconfigurations, behavioral tactics, and content manipulation. Key approaches include deliberately failing email authentication protocols (SPF, DKIM, DMARC), getting blacklisted by sending unsolicited bulk email or hosting malware, using spam trigger words and deceptive subject lines, employing poor HTML coding and suspicious URL shorteners, sending from low-reputation IPs or cheap VM providers, generating high spam complaint rates, using purchased email lists, sending to spam traps (honeypots), including seedlist addresses, violating RFC 5322 email formatting standards, and using content commonly found in spam emails (e.g., urgent language, 'get rich quick' schemes). Success in reaching the spam folder hinges on triggering spam filters and negatively impacting sender reputation.
Key findings
- Authentication Failures: Failing email authentication (SPF, DKIM, DMARC) signals a lack of sender verification, increasing spam classification.
- Blacklisting: Sending unsolicited bulk email or hosting malware leads to blacklisting, ensuring delivery to the spam folder.
- Spam Trigger Words: Using spam trigger words (e.g., 'free,' 'guarantee'), deceptive subject lines, or excessive punctuation triggers spam filters.
- Poor Coding & URL Shorteners: Sloppy HTML coding, excessive use of images without alt text, and suspicious use of URL shorteners raise spam flags.
- Low Reputation IPs: Sending from low-reputation IPs, cheap VM providers, or un-warmed IPs damages sender reputation, causing emails to land in spam.
- Spam Complaints & Purchased Lists: High spam complaint rates and using purchased email lists negatively impact reputation and trigger spam filters.
- Spam Traps & Seedlists: Sending emails to spam traps (honeypots) and including seedlist addresses are methods to ensure an email is flagged as spam.
- RFC 5322 Violations: Intentionally violating RFC 5322 email formatting standards triggers spam filters.
- Spam-Like Content: Using content similar to common spam emails (urgent language, 'get rich quick' schemes) causes spam filters to activate.
Key considerations
- Sender Reputation Damage: Many of these techniques damage sender reputation, potentially harming future deliverability to the inbox.
- Ethical Implications: Intentionally triggering spam filters can be unethical and may violate email marketing guidelines.
- Technical Expertise Required: Successfully employing some of these methods requires technical knowledge of email protocols and formatting standards.
- Monitoring Needed: Monitoring deliverability is crucial to understanding the impact of these actions and to prevent unintended consequences.
What email marketers say
11 marketer opinions
Intentionally delivering emails to the spam folder can be achieved through various techniques that mimic spam-like behavior. These include using spam trigger words, failing email authentication, getting blacklisted, using URL shorteners suspiciously, employing poor HTML coding, sending from low-reputation IPs, generating high spam complaint rates, using purchased email lists, sending to spam traps, and manipulating content to trigger spam filters. Some techniques, such as failing authentication or getting blacklisted, can have negative long-term consequences on overall deliverability.
Key opinions
- Spam Triggers: Using spam trigger words, deceptive subject lines, or excessive punctuation increases the likelihood of being flagged as spam.
- Authentication Failures: Failing SPF, DKIM, or DMARC authentication protocols can lead to emails being classified as spam due to lack of sender verification.
- Blacklisting: Getting an IP address or domain blacklisted by reputable blocklists will almost certainly result in emails landing in spam folders.
- Technical Deficiencies: Poor HTML coding, excessive use of images without alt text, and suspicious use of URL shorteners can negatively impact deliverability.
- Reputation Issues: Sending from low-reputation IPs, not warming up new IPs, and maintaining high spam complaint rates can damage sender reputation and cause emails to be marked as spam.
- List Quality: Using purchased email lists leads to high bounce rates and spam complaints, signaling to ISPs that the sender is engaging in spam practices.
- Spam Traps: Sending emails to known spam traps will negatively impact sender reputation and future deliverability.
- Content Manipulation: Altering email content to trigger spam filters, such as using urgent language, 'get rich quick' schemes, or including seedlist addresses can result in delivery to spam.
Key considerations
- IP Reputation: Using a dedicated IP address and carefully managing its reputation is crucial to avoid long-term deliverability issues.
- Ethical Implications: Intentionally sending emails to the spam folder can have negative consequences for sender reputation and may violate email marketing best practices.
- Long-Term Impact: Certain actions, like getting blacklisted or generating a high spam complaint rate, can have lasting effects on overall email deliverability and sender reputation.
- Filter Variability: Spam filters vary between providers, so a technique that works for one provider may not work for another.
Marketer view
Email marketer from Email on Acid suggests that using URL shorteners (like bit.ly) extensively or in a suspicious manner can negatively impact deliverability. As malicious actors often abuse them, filters will assume the worst.
10 Apr 2025 - Email on Acid
Marketer view
Marketer from Email Geeks recommends sending from a cheap VM provider's IP space, such as OVH or DigitalOcean, as these may have a worse reputation.
10 Oct 2021 - Email Geeks
What the experts say
4 expert opinions
To intentionally deliver emails to the spam folder, experts suggest employing methods that mimic spam signals, such as including URLs listed on the Spamhaus blocklist, sending to known spam traps (honeypots), including seedlist addresses, and using content commonly found in spam emails, like urgent language or 'get rich quick' schemes. These tactics are designed to trigger spam filters and negatively impact sender reputation.
Key opinions
- Blacklisted URLs: Including URLs listed on blocklists like Spamhaus is a reliable way to trigger spam filters.
- Spam Traps: Sending emails to honeypots (spam traps) damages sender reputation and future deliverability.
- Seedlists: Using seedlist addresses can help identify if an email is heading to the spam folder, they also will often direct the email to the spam folder.
- Spam-like Content: Using content commonly found in spam, such as urgent language or 'get rich quick' schemes, triggers spam filters.
Key considerations
- Sender Reputation: Many of these methods negatively impact sender reputation, potentially affecting future deliverability to inboxes.
- Ethical Implications: Intentionally triggering spam filters can be seen as unethical and may violate email marketing guidelines.
- Monitoring: Monitoring deliverability is important to understand the impact of these techniques.
Expert view
Expert from Word to the Wise shares that a method to ensure an email is recognised as spam is to include 'seedlist' addresses to determine how certain mail programs will act, as these are designed to test deliverability into spam folders.
12 Apr 2023 - Word to the Wise
Expert view
Expert from Spam Resource explains that sending email to known spam traps (honeypots) will negatively impact your sender reputation and increase the likelihood of future emails being delivered to the spam folder. Hitting known honeypots will trigger filtering systems.
17 Jan 2024 - Spam Resource
What the documentation says
5 technical articles
Documentation outlines several technical and behavioral factors that lead to emails being classified as spam. These include sending unsolicited bulk email or hosting malware (leading to blacklisting), deliberately misconfiguring DKIM signatures, violating RFC 5322 email formatting standards, having a poor SenderBase reputation due to spam complaints, and maintaining consistently low domain and IP reputation scores according to Google Postmaster Tools. These actions signal to email providers that the sender is engaging in spam-like activities, resulting in emails being routed to the spam folder.
Key findings
- Blacklisting Factors: Sending unsolicited bulk email (spam) and hosting malware are primary reasons for being listed on blocklists like Spamhaus.
- DKIM Misconfiguration: Deliberately misconfiguring DKIM signatures or sending emails without proper DKIM signing increases the likelihood of spam classification.
- RFC Violations: Intentionally violating RFC 5322 email formatting standards can trigger spam filters.
- SenderBase Reputation: A poor SenderBase reputation, often due to spam complaints, leads to emails being classified as spam.
- Google Reputation Scores: Consistently low domain and IP reputation scores in Google Postmaster Tools directly correlate with higher spam rates in Gmail.
Key considerations
- Technical Expertise: Successfully implementing these techniques requires a solid understanding of email protocols (SPF, DKIM, DMARC) and email formatting standards (RFC 5322).
- Ethical Implications: Intentionally sending emails to the spam folder might violate email marketing best practices and could be seen as unethical in some contexts.
- Monitoring and Analysis: Regularly monitoring domain and IP reputation through tools like Google Postmaster Tools and SenderBase is essential for understanding the impact of these actions.
- Reverse Engineering: Analyzing why emails land in spam can provide insights into improving inbox placement, but reverse engineering spam techniques could lead to unintended consequences.
Technical article
Documentation from Spamhaus explains that sending unsolicited bulk email (spam) or hosting malware are key reasons for getting listed on their blocklists, ensuring that email is routed to the spam folder by many providers.
24 May 2022 - Spamhaus
Technical article
Documentation from IETF explains that intentionally violating RFC 5322, the standard for email format, can trigger spam filters. This includes malformed headers, missing required fields, or incorrect character encoding.
10 Nov 2021 - IETF
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