How can I intentionally send a newsletter to the spam folder?

Summary

To intentionally send a newsletter to the spam folder, experts and marketers suggest a variety of techniques. These include sending from misconfigured servers like AWS without proper DNS or authentication, using tools like SWAKS to send raw messages, including the GTUBE string, and using a cheap VPS for sending. Other methods involve employing spam trigger words, URL shorteners, and poorly coded HTML with high image-to-text ratios. Not having email authentication (SPF, DKIM, DMARC) or a segmented and double opt-in list also contributes. Getting blacklisted and triggering Spam Eating Monkeys (SEMs) are other ways, as well as using malformed MIME types and unusual headers.

Key findings

  • Infrastructure and Configuration: Sending from misconfigured servers (AWS without proper DNS) or using tools to send raw messages increases spam likelihood.
  • Content and Formatting: Using spam trigger words, URL shorteners, poorly coded HTML, and high image-to-text ratios in the content raise the chance of spam classification.
  • Authentication and Reputation: Lacking email authentication (SPF, DKIM, DMARC), sending from a new IP, or getting blacklisted significantly increases the likelihood of emails landing in the spam folder.
  • List Management: Not segmenting email lists and failing to use double opt-in can negatively impact engagement and increase spam complaints.
  • Deliberate Spam Triggers: Specific elements like the GTUBE string and triggering SEMs are designed to trigger spam filters.
  • Header Manipulation: Malformed MIME types and unusual headers can confuse spam filters and raise spam scores.

Key considerations

  • Ethical Implications: Intentionally sending emails to spam can damage sender reputation and could violate anti-spam laws. Ensure compliance and ethical considerations are addressed.
  • Testing Environment: Use a controlled environment with dedicated infrastructure (e.g., a separate VPS) to avoid impacting legitimate email sending practices.
  • Understanding Spam Filters: Familiarize yourself with common spam filtering techniques and criteria to effectively target spam filters.
  • Monitoring Results: Closely monitor the results of your actions to understand which techniques are most effective and to gauge the potential impact on deliverability.
  • Compliance: Ensure all activities are within legal and ethical guidelines. Avoid actual spamming, and respect user privacy.
  • Reversibility: Consider the reversibility of any actions taken, especially with blacklisting, as removal can be a complex process.

What email marketers say
9Marketer opinions

To intentionally send a newsletter to the spam folder, marketers suggest employing several techniques known to trigger spam filters. These include using spam trigger words, URL shorteners, and poorly coded HTML with high image-to-text ratios. Sending from a new IP address or domain without proper email authentication (SPF, DKIM, DMARC) or a segmented and double opt-in list also contributes to spam placement. Including the GTUBE string, sending from the command line via a cheap VPS, and getting blacklisted are other methods.

Key opinions

  • Content: Using spam trigger words, excessive punctuation, and high image-to-text ratios in the content increases the chance of emails being flagged as spam.
  • Technical Setup: Sending from new IP addresses or domains without established reputation and proper email authentication significantly increases the likelihood of landing in the spam folder.
  • HTML Coding: Poorly coded HTML emails, especially with excessive images and broken links, are often flagged as spam.
  • List Management: Not segmenting email lists and failing to use double opt-in can negatively impact engagement and increase spam complaints.
  • Deliberate Spam Triggers: Specific elements, like the GTUBE string, are designed to trigger spam filters and can be intentionally used.

Key considerations

  • Ethical Implications: Intentionally sending emails to spam can harm sender reputation and potentially violate anti-spam laws. Ensure compliance and ethical considerations are addressed.
  • Testing Environment: Use a controlled environment with dedicated infrastructure (e.g., a separate VPS) to avoid impacting legitimate email sending practices.
  • Understanding Spam Filters: Familiarize yourself with common spam filtering techniques and criteria to effectively target spam filters.
  • Monitoring Results: Closely monitor the results of your actions to understand which techniques are most effective in triggering spam filters and to gauge the potential impact on deliverability.
  • Compliance: Ensure all activities are within legal and ethical guidelines. Avoid actual spamming, and respect user privacy.
Marketer view

Email marketer from ActiveCampaign shares that not using double opt-in could impact your spam results. Those who confirm their email list are more engaged.

September 2022 - ActiveCampaign
Marketer view

Email marketer from HubSpot Blog shares that using URL shorteners can sometimes flag an email as spam, as spammers often use them to hide malicious links. Direct, full URLs are preferable.

September 2024 - HubSpot Blog
Marketer view

Email marketer from Mailchimp Blog explains that using spam trigger words, like 'free' or excessive punctuation in the subject line or body of the email, can increase the likelihood of the email being flagged as spam.

January 2025 - Mailchimp Blog
Marketer view

Marketer from Email Geeks suggests including the GTUBE string in the message body to help send emails to spam.

January 2024 - Email Geeks
Marketer view

Email marketer from Sendinblue explains using a high image-to-text ratio makes it more likely to be flagged as spam because spammers will often fill their email with images to avoid text based spam filters

May 2022 - Sendinblue
Marketer view

Email marketer from Email Marketing Forum responds that sending from a new IP address or domain with no established reputation is a surefire way to land in the spam folder. Lack of email authentication (SPF, DKIM, DMARC) also contributes.

May 2024 - Email Marketing Forum
Marketer view

Email marketer from Reddit explains that poorly coded HTML emails with excessive use of images, especially without alt text, and broken links are red flags for spam filters.

September 2024 - Reddit
Marketer view

Marketer from Email Geeks shares a way to send free emails from the command line using a $2 VPS with a fresh IP.

April 2023 - Email Geeks
Marketer view

Email marketer from MarketingProfs shares not segmenting your email list could impact your spam results. The more targeted your list is, the more positive engagement you'll receive.

October 2022 - MarketingProfs

What the experts say
4Expert opinions

To intentionally send a newsletter to the spam folder, experts suggest several methods. Sending mail from an AWS instance without proper DNS setup or authentication, using SWAKS to send raw messages, getting blacklisted, and triggering Spam Eating Monkeys (SEMs) are highlighted as effective techniques.

Key opinions

  • Infrastructure Misconfiguration: Sending emails from improperly configured servers (e.g., AWS without reverse DNS or authentication) can lead to spam placement.
  • Raw Message Sending: Using tools like SWAKS to send raw messages directly can bypass some filters and increase the chance of being marked as spam.
  • Blacklist Inclusion: Getting an IP or domain blacklisted is a reliable way to ensure emails are consistently sent to the spam folder.
  • Spam Filter Training: Triggering Spam Eating Monkeys (SEMs) helps train spam filters, leading to future emails being classified as spam.

Key considerations

  • Ethical Implications: Intentionally causing emails to be marked as spam has ethical implications and could damage your sender reputation or result in penalties.
  • Control and Monitoring: Carefully control and monitor the process to avoid unintended consequences on legitimate email sending activities.
  • Testing Purposes: These techniques are generally only suitable for testing or research purposes in a controlled environment.
  • Legal Compliance: Ensure compliance with all applicable laws and regulations regarding email sending and spam.
  • Reversibility: Consider the reversibility of any actions taken, especially with blacklisting, as removal can be a complex process.
Expert view

Expert from Email Geeks suggests sending mail from an AWS instance without setting up reverse DNS or authentication to send emails to spam.

May 2023 - Email Geeks
Expert view

Expert from Spam Resource explains that getting your sending IP or domain listed on public blacklists (like Spamhaus or SORBS) will almost guarantee your emails land in the spam folder.

August 2021 - Spam Resource
Expert view

Expert from Email Geeks recommends using SWAKS from your home broadband network direct to MX to send a raw message out to help send emails to spam.

September 2024 - Email Geeks
Expert view

Expert from Word to the Wise responds that Spam Eating Monkeys (SEM) are systems that automatically report unsolicited emails, helping to train spam filters. Sending emails likely to be caught by SEMs will increase the chances of spam placement.

September 2021 - Word to the Wise

What the documentation says
5Technical articles

According to documentation, sending a newsletter intentionally to the spam folder can be achieved by manipulating email headers, authentication, and overall structure in ways that are inconsistent with standard email protocols. This includes using malformed MIME types, omitting or invalidating DKIM signatures, not implementing a DMARC policy, and employing unusual or excessive header fields. SpamAssassin identifies such deviations through header and text analysis, DNS blocklists, and collaborative filtering, contributing to spam classification.

Key findings

  • Header Manipulation: Using malformed MIME types and unusual or non-standard headers can trigger spam filters.
  • Authentication Failure: Missing or invalid DKIM signatures and a lack of DMARC policy make it easier for spam filters to classify emails as spam due to verification failures.
  • SpamAssassin Analysis: SpamAssassin utilizes multiple methods, including header analysis and DNS blocklists, to identify spam characteristics.

Key considerations

  • Ethical Implications: Deliberately sending emails to the spam folder can damage sender reputation and may violate anti-spam policies.
  • Potential for Misclassification: Using these techniques can lead to unintended misclassification of legitimate emails as spam.
  • Complexity: Manipulating email headers and authentication protocols requires a deep understanding of email standards and spam filtering mechanisms.
  • Testing Environment: Implement these techniques only in a controlled testing environment to avoid impacting real-world deliverability.
  • Compliance: Ensure all activities comply with applicable email marketing laws and regulations.
Technical article

Documentation from RFC Editor shares that using incorrect or malformed MIME types in the email header can confuse spam filters and increase the spam score, as it deviates from standard email formatting.

January 2025 - RFC 7231
Technical article

Documentation from RFC Editor explains that using unusual or malformed headers, or including excessive or non-standard header fields, can raise suspicion and cause spam filters to flag the email.

May 2021 - RFC 5322
Technical article

Documentation from SpamAssassin explains that SpamAssassin is an email spam filter program. It identifies spam using a variety of mechanisms including header and text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases.

December 2022 - SpamAssassin
Technical article

Documentation from DKIM.org explains that a missing or invalid DKIM signature can lead to emails being marked as spam, as it fails to verify the sender's identity and authenticity.

July 2023 - DKIM.org
Technical article

Documentation from DMARC.org explains that not setting up a DMARC policy allows spammers to more easily spoof your domain, which can negatively affect your sender reputation and lead to deliverability issues, including being marked as spam.

July 2022 - DMARC.org