Summary
Emails suddenly going to spam in Gmail can be attributed to a complex interplay of factors affecting sender reputation, email content, and recipient engagement. Key issues include problematic links (unusual URLs, flagged tracking domains), a decline in sender reputation necessitating IP warming and authentication, blacklisting, increased spam complaints, shared IP issues, poor ESP practices, lack of subscriber engagement, spam-triggering content, and failure to monitor feedback loops. Implementing solutions like using CNAMEs, warming IPs, cleaning lists, monitoring FBLs, avoiding URL shorteners, reviewing content, segmenting lists, A/B testing, and choosing reputable ESPs are crucial for improving deliverability.
Key findings
- Problematic Links: Unusual links, mentions of problematic domains, specific S3 buckets, and flagged ESP tracking domains can trigger spam filters. Tools like Aboutmy.email can identify these issues.
- Sender Reputation Decline: A drop in sender reputation, often due to new IPs or increased volume, requires gradual IP warming and ensuring proper email authentication (SPF, DKIM, DMARC).
- Blacklisting: Being blacklisted significantly impacts deliverability; check your IP/domain against blacklists.
- Spam Complaints: Increased spam complaints trigger filters; reduce frequency and ensure opt-in.
- Shared IP Issues: Shared IPs can be affected by other senders' actions; consider a dedicated IP.
- ESP Practices: Choose an ESP with a good reputation and adherence to best practices.
- Lack of Engagement: Low subscriber engagement hurts deliverability; encourage interaction and remove inactives.
- Content Triggers: Certain words, phrases, or URL patterns in your email can trigger spam filters.
- Unmonitored FBLs: Failure to monitor and address feedback loops leads to unaddressed spam complaints.
Key considerations
- Analyze Links: Thoroughly analyze email links for potential issues using available tools.
- Warm IPs Carefully: Gradually warm new IPs to establish a positive sending reputation.
- Maintain List Hygiene: Regularly clean your email list by removing inactive subscribers and verifying addresses.
- Monitor FBLs Actively: Implement and monitor feedback loops to address spam complaints promptly.
- Avoid URL Shorteners: Use full, transparent URLs instead of URL shorteners.
- Review Email Content: Carefully review email content for spam-triggering elements.
- Segment Lists: Segment your lists for more targeted and relevant content to increase engagement.
- A/B Test: A/B test subject lines, content, and send times to optimize engagement.
- Monitor Placement: Monitor email placement using seed lists and testing tools.
What email marketers say
12 marketer opinions
Emails suddenly landing in Gmail's spam folder can be attributed to various factors affecting sender reputation and email content. These include issues with link tracking domains, a drop in sender reputation necessitating IP warming and email authentication, being blacklisted, increased spam complaints, using shared IPs, poor ESP practices, lack of subscriber engagement, and problematic email content. Monitoring email placement, segmenting lists, and A/B testing can improve deliverability.
Key opinions
- Link Tracking Issues: Problems with ESP-provided link tracking root domains can trigger spam filters; using CNAME/domain aliases might help.
- Sender Reputation: A sudden drop in sender reputation requires IP warming, email authentication (SPF, DKIM, DMARC), and cleaning email lists.
- Blacklisting: Check if your IP or domain is blacklisted, as this severely impacts deliverability.
- Spam Complaints: Increased spam complaints from recipients can trigger spam filters; reduce sending frequency and ensure opt-in.
- Shared IPs: Using a shared IP can negatively impact deliverability due to the actions of other senders; consider a dedicated IP.
- ESP Practices: Ensure your email service provider (ESP) has a good reputation and follows best practices.
- Subscriber Engagement: Low subscriber engagement (opens, clicks, replies) hurts deliverability; encourage interaction and remove inactive users.
Key considerations
- Monitor Placement: Use seed lists and inbox placement testing tools to identify if emails are landing in spam.
- Segmentation: Segment email lists to send targeted content, increasing relevance and reducing spam complaints.
- A/B Testing: A/B test subject lines, content, and send times to improve engagement and reduce spam flagging.
- Domain reputation: Regularly monitor domain reputation and keep a high level of awareness
Marketer view
Email marketer from Reddit suggests that a sudden increase in spam complaints from recipients could trigger Gmail's spam filters. Reducing sending frequency and ensuring recipients have opted-in can help.
15 Apr 2025 - Reddit
Marketer view
Email marketer from Email Marketing Forum suggests that if you're using a shared IP address, the actions of other senders on that IP can impact your deliverability. Consider switching to a dedicated IP address for more control.
5 May 2023 - Email Marketing Forum
What the experts say
6 expert opinions
Emails landing in Gmail spam can stem from several issues, including problematic links within the email, a sudden drop in sender reputation requiring IP warming, poor list hygiene, failure to monitor feedback loops (FBLs), and the use of URL shorteners. Analyzing email links and hostnames with tools like Aboutmy.email, maintaining a clean and engaged email list, monitoring and addressing FBLs, and avoiding URL shorteners can help prevent emails from being flagged as spam.
Key opinions
- Unusual Links: Unusual links, mentioning problematic domains, or specific S3 buckets can trigger spam filters.
- Link Analysis: Tools like Aboutmy.email can help identify link and hostname issues.
- Sender Reputation Decline: A sudden drop in sender reputation necessitates gradual IP warming, especially after acquiring a new IP or increasing sending volume.
- List Hygiene: Maintaining a clean, engaged email list by removing inactive subscribers and verifying addresses improves deliverability.
- Feedback Loops (FBLs): Monitoring and understanding feedback loops is crucial for identifying and addressing spam complaints.
- URL Shorteners: Using URL shorteners can negatively impact deliverability due to their association with spam.
Key considerations
- Investigate Links: Thoroughly examine all links in your emails for potential issues.
- Warm-Up IPs: Gradually warm up new IPs or sending volume increases to establish a positive sender reputation.
- Clean Your List: Regularly remove unengaged subscribers and verify email addresses.
- Monitor FBLs: Implement and actively monitor feedback loops to address spam complaints promptly.
- Avoid Shorteners: Use full, transparent URLs instead of URL shorteners.
Expert view
Expert from Email Geeks recommends using Aboutmy.email to identify potential link and hostname issues that might be causing spam problems.
9 Nov 2023 - Email Geeks
Expert view
Expert from Word to the Wise warns against using URL shorteners in emails, as they can be associated with spam and malicious activity. Using full, transparent URLs is recommended to improve deliverability and build trust with recipients.
13 Aug 2024 - Word to the Wise
What the documentation says
4 technical articles
Gmail's spam filtering is influenced by sender reputation, email content, and user reports. Sudden shifts in these elements can lead to spam placement. Proper email authentication (SPF, DKIM, DMARC) is crucial, and failure to authenticate, particularly after changes in sending practices, can result in emails being flagged as spam. Specific words, phrases, or URL patterns within the email content can also trigger spam filters. Maintaining a strong sender reputation by consistently delivering valuable content and adhering to best practices is essential for email deliverability.
Key findings
- Gmail Algorithm: Gmail uses a complex algorithm that considers sender reputation, email content, and user reports for spam filtering.
- Authentication: Email authentication (SPF, DKIM, DMARC) is vital to avoid spam flagging, especially after changes in sending practices.
- Content Triggers: Specific words, phrases, or URL patterns in your email can trigger spam filters.
- Sender Reputation: Maintaining a good sender reputation by sending valuable content is essential for deliverability.
Key considerations
- Monitor Factors: Monitor changes in sender reputation, email content, and user reports that might affect spam placement.
- Implement Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is in place and regularly reviewed.
- Review Content: Regularly review email content to avoid using spam-triggering words, phrases, or URL patterns.
- Provide Value: Consistently provide valuable and engaging content to recipients to maintain a positive sender reputation.
Technical article
Documentation from SparkPost explains that certain words, phrases, or URL patterns within your email content can trigger spam filters. Reviewing your content and avoiding common spam triggers is crucial.
3 Aug 2023 - SparkPost
Technical article
Documentation from Microsoft outlines that maintaining a good sender reputation is critical for email deliverability. Consistently sending valuable content and adhering to best practices are key to building and maintaining a positive reputation.
22 Jul 2024 - Microsoft
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