Summary
Fixing an IP address issue is a crucial first step in resolving email deliverability problems, but it's often not the complete solution. Even after an IP address is cleared from blocklists or updated, emails may still land in the spam folder. This persistence often stems from other underlying factors related to sender reputation, email authentication, content, and recipient engagement.
Key findings
- Reputation lag: Domain reputation can lag behind IP reputation. Even with a new or clean IP, a historically poor domain reputation will continue to affect inbox placement.
- Authentication issues: Missing or misconfigured SPF, DKIM, or DMARC records can severely impact email trust, regardless of IP status. Even personal emails from a custom domain need proper setup.
- Content and engagement: Spam filters analyze email content, subject lines, and recipient engagement. Low engagement, high complaint rates, or spammy content can trigger filters even with a clean IP.
- Hidden blocklists: An IP or domain might be listed on less common or private blacklists that aren't immediately apparent through basic checks.
Key considerations
- Comprehensive auditing: Beyond IP address checks, conduct a full audit of your domain's authentication records (SPF, DKIM, DMARC) and ensure they are correctly implemented. You can use a free DMARC record generator tool for this.
- Monitor sender reputation: Regularly check your domain and IP reputation using tools like Google Postmaster Tools. This helps identify ongoing issues beyond a single IP blacklisting. For more, see our guide on understanding your email domain reputation.
- Improve engagement: Focus on sending relevant, valuable content to engaged recipients. Low engagement or a high spam complaint rate can signal to mailbox providers that your emails are unwanted. Mailgun provides tips to avoid emails going to spam in general.
- Review content and sending patterns: Analyze your email content for spammy keywords, excessive images, or poor formatting. Also, ensure your sending volume and frequency are consistent and appropriate.
What email marketers say
Email marketers frequently encounter situations where emails continue to land in spam despite initial fixes, such as resolving an IP blocklist issue. Their experiences often highlight the multifactorial nature of deliverability, pointing to domain reputation, content quality, and recipient engagement as critical elements that override a clean IP address.
Key opinions
- Domain reputation matters more: Many marketers find that even if their IP is clean, a tarnished domain reputation from past issues can keep emails out of the inbox. This issue is common with new dedicated IPs.
- Unsubscribe options: A common oversight is the absence of an easy and functional unsubscribe mechanism, which can significantly increase spam complaints and impact deliverability.
- Content-driven filtering: Spam filters increasingly analyze content for spammy characteristics, such as too many images or certain keywords, even for standard emails.
- Low engagement: When subscribers don't engage with emails, or if mailbox usage is low, it signals to ISPs that the emails are unwanted, contributing to spam placement.
- Non-obvious reasons: Marketers often discover that reasons for emails going to spam are not always clear-cut, requiring deeper investigation beyond initial technical checks.
Key considerations
- Comprehensive reputation checks: Marketers should consistently monitor both IP and domain blacklists and blocklists, as well as sender reputation scores, to catch any lingering issues. This can be supported by blocklist monitoring.
- User experience: Prioritize a clear and easy unsubscribe process. This can reduce spam complaints and improve overall sender reputation.
- Content optimization: Review email content for common spam triggers, balancing text-to-image ratios and avoiding suspicious phrasing. Optimizing content is key to avoiding spam. Learn more about why your emails are going to spam in 2024.
- Engagement strategies: Implement strategies to boost recipient engagement, ensuring emails are opened, clicked, and replied to. This is a strong positive signal for mailbox providers, as highlighted by OptinMonster.
Marketer view
A marketer from Email Geeks notes that even after fixing an outdated IP address, their client's emails continued to land in spam a couple of months later, suggesting a potential lingering reputation issue from past spam incidents.
Marketer view
A marketer from Email Geeks observes that standard one-to-one emails to customers are still going to spam, indicating a problem beyond just bulk mail deliverability.
What the experts say
Email deliverability experts underline that a clean IP address is merely one piece of a complex puzzle. They frequently emphasize the overarching importance of domain reputation, proper email authentication (SPF, DKIM, DMARC), and consistent, trustworthy sending practices. Even subtle misconfigurations or unusual sending behaviors can negate the benefit of a newly cleared IP.
Key opinions
- Authentication is fundamental: Experts consistently point to email authentication protocols, particularly SPF and DMARC, as foundational checks. Broken or missing SPF and a lack of DKIM signing can lead to delivery issues, especially with major providers like Gmail.
- Beyond IP: While an IP blocklist is a severe issue, experts note that simply fixing the IP address doesn't address other factors that make B2B emails appear suspicious, such as sending outreach-style emails via standard business accounts.
- DMARC rejections: If DMARC is broken, it typically results in rejections, not just spam folder placement. If emails are going to spam without rejections, DMARC may not be the primary cause, though a full DMARC monitoring setup is always beneficial.
- Gmail's flexibility: Gmail has historically used best guess SPF to work around missing or broken SPF records, suggesting that SPF alone might not be the sole cause of spam filtering in some cases.
- DKIM misconfigurations: Issues like mis-signing DKIM or an email provider using the wrong d= value for multiple domains can lead to deliverability problems.
Key considerations
- Holistic deliverability review: Beyond IP status, assess all facets of your email program, including authentication, content, and sending infrastructure, to pinpoint root causes.
- Sender behavior: Evaluate whether your sending behavior (e.g., volume, frequency, content) aligns with expectations for standard business emails versus bulk or outreach mail. Understanding why your cold emails go to spam can be helpful here.
- Continuous authentication validation: Regularly verify your SPF, DKIM, and DMARC records for correctness and alignment, as even minor changes can introduce issues. For example, troubleshooting common DMARC issues in Microsoft 365 and Google Workspace is critical.
- DKIM specificity: For organizations with multiple domains or complex sending setups, pay close attention to DKIM signing to ensure the correct d= (domain) is used. Learn more about decoding DKIM temperror.
- Postmaster tools: Leverage tools like Google Postmaster Tools to gain insight into domain reputation, spam rates, and authentication errors, helping identify root causes. Twilio also has insights on why emails go to spam.
Expert view
An expert from Email Geeks advises that checking email authentication, specifically DMARC and SPF, is a primary step when diagnosing deliverability problems.
Expert view
An expert from Email Geeks highlights that insufficient or broken SPF, coupled with a lack of DKIM signing, can lead to deliverability problems, especially with providers like Gmail, irrespective of DMARC.
What the documentation says
Official documentation and technical guides underscore the importance of foundational email protocols beyond just IP reputation. They detail how proper DNS records, authentication (SPF, DKIM, DMARC), and server configurations are essential for establishing trust with mailbox providers and ensuring deliverability. A single missing or incorrect record can lead to emails being flagged as spam.
Key findings
- DNS records are crucial: Adding correct DNS records, such as SPF, is highlighted as a solution to prevent emails from looking like spam. This ensures proper email authentication.
- rDNS mapping: A missing reverse DNS (rDNS) mapping indicates incorrect email server configuration and is a significant factor in emails being flagged as spam.
- New IP reputation: New IP addresses start without any established reputation, meaning major mailbox providers will initially treat emails from them with caution until a positive sending history is built.
- Comprehensive compliance: Compliance with standards like CAN-SPAM, maintaining a good sender reputation, clean lists, and effective subject lines are all identified as factors influencing spam placement.
Key considerations
- Verify DNS and rDNS: Ensure that all necessary DNS records (SPF, DKIM, DMARC) are correctly published and that your email server has a valid rDNS mapping. Refer to a simple guide to DMARC, SPF, and DKIM for basic setup.
- Adhere to best practices: Follow best practices for sender reputation, list hygiene, and content creation. This includes ensuring your emails are CAN-SPAM compliant.
- Warm up new IPs: If you've recently changed or obtained a new IP, follow proper IP warming procedures to gradually build reputation. Even after IP warming, some emails might still go to spam.
- Review technical configurations: Beyond authentication, check your email server's overall configuration. Server Fault provides details on how missing an rDNS mapping can cause problems.
Technical article
Documentation from Mailgun states that understanding why emails end up in spam involves examining factors such as sender domain and IP address, spam complaint rates, and subscriber engagement.
Technical article
Documentation from Twilio lists CAN-SPAM compliance, sender reputation, list cleanliness, and subject lines as key reasons why emails may land in spam folders.
Related resources
10 resources
Related pages
Why are emails from new dedicated IPs and domains landing in spam?
How to fix personal emails going to spam from a custom domain?
Why are my emails going to spam even with a low spam rate?
Why are my low-volume emails going to spam despite having SPF and DKIM set up?
Why am I still having deliverability issues after cleaning my email list?
Why are my emails landing in spam even though they pass SPF, DKIM, and DMARC?
An in-depth guide to email blocklists
A simple guide to DMARC, SPF, and DKIM
A practical guide to understanding your email domain reputation
Why Your Emails Fail: Expert Guide to Improve Email Deliverability [2025]
