Summary
Test emails landing in the junk folder is a multifaceted problem with technical, content-related, and engagement-based factors. Technical aspects include poor authentication (SPF, DKIM, DMARC), high spam rates, and inadequate IP warm-up. Content issues involve spam trigger words, excessive images, and generic templates. Engagement is critical; low engagement leads to junk folder placement. Effective solutions involve proper authentication setup, spam rate monitoring, content optimization, list hygiene, IP warm-up, personalized content, and active management of feedback loops. Testing environments often don't accurately represent real-world conditions.
Key findings
- Authentication is Key: Properly configured SPF, DKIM, and DMARC records are essential for establishing sender legitimacy and preventing spoofing.
- Spam Rate Matters: Maintaining a low spam rate (below 0.10% and never exceeding 0.30%) is crucial for avoiding the junk folder.
- Engagement Drives Placement: Mailbox providers heavily prioritize user engagement when determining inbox placement; low engagement leads to spam.
- Content Impacts Deliverability: Using spam trigger words, excessive images, and generic templates can trigger spam filters.
- Testing Isn't Always Realistic: Testing deliverability with small, internal groups doesn't accurately reflect real-world conditions affecting inbox placement.
Key considerations
- Implement Authentication: Configure SPF, DKIM, and DMARC records for your sending domain to authenticate your emails.
- Monitor Spam Rate: Regularly monitor your spam rate through tools like Google Postmaster Tools and address any spikes promptly.
- Optimize Content: Avoid spam trigger words, excessive images, and other elements that might trigger spam filters; personalize your content to increase engagement.
- Maintain List Hygiene: Regularly clean your email list by removing inactive subscribers and correcting typos.
- Warm-Up IP Gradually: If using a dedicated IP, gradually warm it up by slowly increasing sending volume over time.
- Prioritize Engagement: Send relevant and valuable content that encourages recipients to open, click, and interact with your emails.
- Monitor Feedback Loops: Implement and monitor feedback loops to identify and address subscriber complaints.
What email marketers say
9 marketer opinions
Test emails often land in the junk folder due to factors impacting sender reputation and deliverability. Key issues include poor email authentication (SPF, DKIM, DMARC), low sender reputation, high spam complaint rates, problematic content (spam trigger words, URL shorteners, high image-to-text ratio), and lack of engagement. Improving deliverability involves warming up IP addresses, maintaining good email list hygiene, using dedicated IPs, segmenting email lists, personalizing content, monitoring feedback loops, and A/B testing email elements.
Key opinions
- Sender Reputation: A low sender reputation is a major cause of emails going to the junk folder. Improving and monitoring this reputation is crucial.
- Email Authentication: Proper email authentication (SPF, DKIM, DMARC) is essential to verify the sender's legitimacy and prevent spoofing.
- Engagement Matters: High engagement rates can significantly improve deliverability, while low engagement can lead to emails being marked as spam.
- Content Quality: Problematic content, such as spam trigger words, excessive images, and aggressive sales language, increases the likelihood of emails being flagged as spam.
- List Hygiene: Maintaining a clean email list by removing inactive subscribers and correcting typos helps reduce bounce rates and improves sender reputation.
Key considerations
- IP Warm-up: Gradually increase email volume when using a new IP address to establish a positive sending reputation.
- Personalization: Personalize email content to improve relevance and reduce the chances of being marked as spam, especially for cold emails.
- Feedback Loops: Monitor and address complaints received through feedback loops to identify and fix deliverability issues.
- A/B Testing: Continuously test different email elements (subject lines, content, sending times) to optimize engagement and improve deliverability.
- Dedicated IP: Consider using a dedicated IP address for more control over sender reputation, especially for higher sending volumes.
Marketer view
Email marketer from Word to the Wise explains that feedback loops (FBLs) allow mailbox providers to forward complaints about spam to senders. By monitoring and addressing these complaints, senders can identify and fix issues that are causing their emails to be marked as spam.
23 Apr 2024 - Word to the Wise
Marketer view
Email marketer from Sendinblue shares that to improve email deliverability, it's important to use a dedicated IP address, authenticate your email with SPF and DKIM, monitor your sender reputation, and segment your email list to send more targeted content. Consistent sending volume and engagement also play a role.
19 May 2022 - Sendinblue
What the experts say
4 expert opinions
Test emails often end up in the junk folder due to the artificial nature of the testing environment. Sending small volumes to internal test accounts doesn't accurately reflect real-world conditions where sender reputation and user engagement play significant roles. Deliverability is statistical, and while global filters can be influenced, individual user filters are beyond a sender's control. To improve inbox placement, focus on building a positive sender reputation by sending real emails, properly authenticating your mail, and warming up your IP address gradually. Prioritize engagement, as mailbox providers increasingly use it to determine where to place emails.
Key opinions
- Testing Limitations: Testing deliverability with small, internal groups doesn't accurately simulate real-world conditions affecting inbox placement.
- Deliverability Statistics: Email deliverability is statistical; achieving 100% inbox placement is impossible due to individual user filters.
- Importance of Engagement: Mailbox providers prioritize user engagement when determining inbox placement.
- Sender Reputation: A positive sender reputation is crucial and is built by sending real emails to engaged users.
Key considerations
- Real-World Testing: Transition from internal testing to sending real emails to assess deliverability accurately.
- IP Warm-Up: Gradually warm up your IP address to establish a positive sending reputation with mailbox providers.
- Email Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) to verify your sender legitimacy.
- Focus on Engagement: Implement strategies to increase user engagement, such as sending relevant and valuable content.
Expert view
Expert from Email Geeks explains that if you're not sending significant amounts of mail and not sending to real recipients, your testing may not be particularly meaningful and that as long as your authentication is set up correctly, and you’re acquiring email addresses with the consent of the recipients, your next step would be to send real email. They also add that If you’re on a dedicated IP you’d want to look at warming up your IP / sending domain tuple to introduce your mail stream to the mbp filters gradually.
6 Apr 2024 - Email Geeks
Expert view
Expert from Email Geeks explains that deliverability is statistical and you cannot ensure 100% of your mail makes every inbox ever time. Individual users have individual filters and deliverability ensures that the global filters put mail in the inbox, but once past those filters, it's out of our control.
19 May 2025 - Email Geeks
What the documentation says
4 technical articles
Test emails often end up in the junk folder due to technical reasons related to sender authentication and spam rates. Maintaining a low spam rate (below 0.10%, never exceeding 0.30%) is crucial. Employing SPF records helps to specify authorized mail servers, preventing address forging. DKIM signatures verify message authenticity and integrity. Email clients like Outlook use junk email filters that users can adjust, indicating the importance of both sender-side configuration and recipient behavior.
Key findings
- Spam Rate Thresholds: Maintaining a spam rate below 0.10% (and never exceeding 0.30%) is vital for avoiding the spam folder, according to Google Postmaster Tools.
- SPF Records: SPF records authorize mail servers to send email on behalf of your domain, preventing address forgery.
- DKIM Signatures: DKIM signatures verify the authenticity and integrity of email messages.
- User-Adjustable Filters: Email clients like Outlook use junk email filters that users can adjust, affecting deliverability.
Key considerations
- Monitor Spam Rate: Regularly monitor your spam rate using tools like Google Postmaster Tools and take corrective actions if it approaches or exceeds the threshold.
- Implement SPF: Create and configure SPF records to authorize your mail servers and prevent address forging.
- Implement DKIM: Implement DKIM to digitally sign your email messages, ensuring authenticity and integrity.
- Educate Users: Encourage recipients to mark legitimate emails as 'not junk' to train their email client's filters.
Technical article
Documentation from DKIM.org explains that DomainKeys Identified Mail (DKIM) uses a digital signature to allow the recipient to verify that an email message was sent from an authorized mail server and that the message content was not altered during transit. This authentication method helps improve email deliverability.
17 May 2024 - DKIM.org
Technical article
Documentation from RFC-Editor explains that Sender Policy Framework (SPF) records are used to specify the mail servers that are authorized to send email on behalf of your domain. Creating and properly configuring an SPF record can prevent spammers from forging your email address.
8 Oct 2024 - RFC-Editor
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