How to fix Gmail spam issues during IP warm-up?

Summary

Fixing Gmail spam issues during IP warm-up requires a comprehensive approach encompassing technical setup, sender reputation management, and content optimization. Key factors influencing inbox placement include email authentication (SPF, DKIM, DMARC), engagement metrics, spam complaints, and list hygiene. Experts recommend starting with highly engaged subscribers and gradually increasing volume during IP warming, while closely monitoring deliverability metrics and adhering to Yahoo/Google's specific requirements. Ensure proper authentication, avoid blacklists, and reduce spam complaints by sending valuable, relevant content and making unsubscribing easy. Tools like Google Postmaster Tools and MultiRBL are crucial for monitoring sender and IP reputation. It's also vital to validate email lists, remove bounces, and avoid spam triggers to ensure successful inbox placement.

Key findings

  • Email Authentication: Correctly configuring SPF, DKIM, and DMARC is essential for deliverability. Unauthenticated emails are more likely to be flagged as spam.
  • Sender Reputation: A positive sender reputation is crucial for inbox placement. Monitor and manage your reputation using tools like Google Postmaster Tools.
  • Engagement Metrics: High engagement (opens, clicks) and low spam complaint rates improve deliverability. Focus on sending relevant, engaging content.
  • List Hygiene: Maintaining a clean email list by removing invalid addresses and unengaged subscribers is vital for a good sender reputation.
  • IP Warming Best Practices: Gradually increasing sending volume with engaged subscribers helps build trust with ISPs.
  • New Authentication Standards: Google and Yahoo enforce usage of DKIM and DMARC to be passing. This needs setting up before warming the IP.

Key considerations

  • Start with Engaged Subscribers: Begin IP warm-up by sending emails to your most engaged subscribers to build a positive sender reputation.
  • Gradual Volume Increase: Gradually increase sending volume based on positive engagement signals, carefully monitoring bounces and spam complaints.
  • Content Optimization: Craft valuable, relevant content and avoid spam triggers to improve engagement and reduce spam complaints.
  • Monitor Deliverability Metrics: Continuously monitor bounce rates, spam complaints, and engagement rates to identify and address deliverability issues promptly.
  • Regular List Cleaning: Regularly clean your email list to remove invalid or unengaged subscribers to maintain a good sender reputation.
  • Authentication Setup: Make sure DKIM and DMARC are set up and correctly passing *before* the IP warm-up commences.

What email marketers say
9Marketer opinions

During IP warm-up, Gmail spam issues often stem from factors such as low sender reputation, poor email authentication (SPF, DKIM, DMARC), low engagement metrics, and high spam complaint rates. To resolve these, strategies include ensuring proper email authentication, cleaning email lists to remove invalid or unengaged subscribers, warming up the IP with engaged users before progressively increasing volume, monitoring IP and domain reputation using tools like Google Postmaster Tools and MultiRBL, reviewing content for spam triggers (excessive capitalization, exclamation points, too many links), and using double opt-in to ensure high-quality data and consent. Regularly monitoring metrics and adjusting strategies is essential to maintaining a positive sender reputation and inbox placement.

Key opinions

  • Sender Reputation: Low sender reputation is a primary cause of emails landing in spam. Monitor and improve this using tools like Google Postmaster Tools.
  • Email Authentication: Improperly configured SPF, DKIM, and DMARC can negatively impact deliverability. Ensure these are correctly set up.
  • Engagement Metrics: Low engagement (opens, clicks) and high spam complaints can lead to spam placement. Focus on sending engaging content to interested subscribers.
  • List Hygiene: Sending to invalid or unengaged email addresses negatively affects deliverability. Regularly clean your email lists.
  • Spam Triggers: Certain words and formatting can trigger spam filters. Review content carefully to avoid these triggers.

Key considerations

  • Gradual Warm-up: Start IP warm-up by sending small volumes of email to your most engaged subscribers and gradually increase the volume based on positive engagement signals.
  • Monitoring: Continuously monitor key metrics such as bounce rates, spam complaints, and engagement rates to identify and address deliverability issues.
  • Content Quality: Ensure that your emails provide value to subscribers and avoid using spammy language or formatting.
  • Double Opt-In: Implement double opt-in to ensure that subscribers have explicitly consented to receive your emails.
  • Blacklist Checks: Regularly check your IP address and domain against blacklists to ensure they are not listed.
Marketer view

Email marketer from GMass explains that common causes for going to spam include poor IP reputation, low engagement, spammy content, and incorrect authentication. Resolve the issues by improving IP and domain reputation, engaging subscribers, cleaning email lists, fixing email authentication. <https://www.gmass.co/blog/why-do-my-emails-go-to-spam/>

July 2024 - GMass
Marketer view

Email marketer from WebmasterWorld forum user TechBloke88 shares that checking if the IP and domain aren't blacklisted, making sure you're not on any blocklists is key. Using tools like MultiRBL to check is critical. Clean your list from hard bounces and invalid emails.

September 2021 - WebmasterWorld
Marketer view

Email marketer from Reddit user u/MailGuru shares that if you are consistently ending up in spam after IP warm-up, double-check your list hygiene (remove invalid emails), monitor your IP reputation, and review content for spam triggers. Also, ensure proper email authentication.

February 2025 - Reddit
Marketer view

Email marketer from ZeroBounce explains that inbox placement issues are often caused by low sender reputation, high spam complaint rates, and missing authentication protocols. Fix it by validating emails and using double opt-in to ensure high quality data. Regularly clean email lists of unengaged contacts and keep the complaint rate low. <https://www.zerobounce.net/email-deliverability/why-emails-go-to-spam/>

April 2023 - ZeroBounce
Marketer view

Email marketer from Reddit user u/EmailPro2020 suggests that ensure your emails have a clear 'From' address, a relevant subject line, and easy unsubscribe options. Also, avoid using spam trigger words and test your emails with various spam checkers before sending.

October 2023 - Reddit
Marketer view

Email marketer from Mailjet shares that factors affecting Gmail spam filters include sender reputation, email authentication (SPF, DKIM, DMARC), engagement metrics (opens, clicks), and spam complaints. Monitor these metrics and adjust your strategy accordingly.

April 2023 - Mailjet
Marketer view

Email marketer from Warrior Forum MailKing22 shares that cleaning your email list is very important. Remove any bounces or unengaged subscribers. Only send to users who actively want to receive your emails. <https://www.warriorforum.com/threads/emails-going-to-spam-even-with-dkim-spf-dmarc-correctly-configured.2730361/>

November 2024 - Warrior Forum
Marketer view

Email marketer from Reddit user u/EmailNoob says that spam filters get triggered by factors like using excessive exclamation points, using all caps, and embedding too many links in the body of the email. <https://www.reddit.com/r/emailmarketing/comments/oh5wjg/gmail_always_sending_my_emails_to_spam/>

March 2025 - Reddit
Marketer view

Email marketer from SendGrid explains that for new IPs, warm-up is crucial to establish trust with ISPs like Gmail. Start by sending to your most engaged users and gradually increase volume based on positive engagement signals, while carefully monitoring bounces and spam complaints.

January 2023 - SendGrid

What the experts say
6Expert opinions

Addressing Gmail spam issues during IP warm-up involves a multifaceted approach. Properly implementing DMARC, though essential, doesn't guarantee inbox delivery; engagement is crucial. It's vital to adhere to Yahoo/Google's specific requirements, focusing on volume limitations and prioritizing engaged subscribers during IP warming. Ensuring SPF, DKIM, and DMARC authentication, along with monitoring sender reputation through tools like Google Postmaster Tools, are key. Avoiding blacklisting, reducing spam complaints, and consistently delivering engaging content are also essential for optimizing inbox placement. Furthermore, new authentication requirements dictate that DKIM and DMARC must be passing, emphasizing the importance of setting this up before initiating the IP warm-up process.

Key opinions

  • Engagement Matters: High engagement and low complaint rates are critical for Gmail inbox placement, even with correct DMARC implementation.
  • Yahoo/Google Requirements: Adhering to specific requirements from Yahoo and Google is essential for successful IP warming and deliverability.
  • Authentication is Crucial: Correctly configuring SPF, DKIM, and DMARC is a prerequisite for IP warm-up and improved deliverability.
  • Sender Reputation: Monitoring sender reputation via Google Postmaster Tools is vital for identifying and addressing deliverability issues.
  • Blacklisting Avoidance: Ensuring your sending IPs are not blacklisted is essential to avoid being blocked by Gmail.

Key considerations

  • Prioritize Engagement: Focus on sending engaging content and targeting your most active subscribers during the IP warming process.
  • Volume Limits: Limit sending volume during IP warming and gradually increase it based on positive engagement signals.
  • Proactive Monitoring: Continuously monitor key metrics such as bounce rates, spam complaints, and engagement rates to identify and address deliverability issues promptly.
  • Content Relevance: Segment your email lists and send content that is relevant to each segment to improve engagement and reduce spam complaints.
  • Pre-Warm Authentication: Ensure that DKIM and DMARC are correctly set up and passing *before* you begin the IP warming process to comply with new authentication requirements.
Expert view

Expert from Spamresource shares that to avoid spam issues when warming IPs, you should start with a small number of highly engaged subscribers and gradually increase volume. Authenticate email using SPF, DKIM, and DMARC, and monitor your sender reputation using Google Postmaster Tools. Also, segment your lists and send relevant content to each segment. <https://www.spamresource.com/2016/01/warming-ip-address-right-way.html>

January 2025 - Spamresource
Expert view

Expert from Email Geeks explains that properly implemented DMARC doesn't guarantee inbox delivery and Gmail inbox placement depends on both getting the technical bits right AND driving high engagement. Low engagement (or high complaints) on perfectly configured mail will impede inbox delivery.

October 2021 - Email Geeks
Expert view

Expert from Email Geeks shares that Unspam is claiming the user’s SPF is failing.

March 2022 - Email Geeks
Expert view

Expert from Word to the Wise shares that the new authentication requirements for Google and Yahoo require DKIM and DMARC to be used and be passing, this needs to be set up before you warm up an IP. <https://wordtothewise.com/2023/06/gmail-yahoo-authentication-enforcement/>

April 2023 - Word to the Wise
Expert view

Expert from Spamresource explains that to address Gmail blocking emails, verify your sending IPs aren't blacklisted, ensure proper authentication (SPF, DKIM, DMARC), and that your sending practices align with Gmail's guidelines. Reduce spam complaints and send engaging content. <https://www.spamresource.com/2012/02/gmail-blocking-your-mail-what-to-do.html>

July 2024 - Spamresource
Expert view

Expert from Email Geeks shares to start with making sure you're following the Yahoo/Google requirements properly and then when going through IP warming make sure you're limiting volume per the IP warming process and also focusing on most engaged or newest subscribers. Refers to <https://www.spamresource.com/2024/01/yahoo-mailgmail-2024-easy-sender.html>

January 2023 - Email Geeks

What the documentation says
4Technical articles

Improving Gmail deliverability during IP warm-up requires establishing a positive sender reputation and adhering to best practices. Essential steps include proper setup of SPF, DKIM, and DMARC for email authentication, avoiding sending unsolicited emails, maintaining a clean email list by removing bounces, ensuring high-quality and valuable content, and monitoring spam complaints. A gradual IP warm-up process, starting with small volumes to engaged users and incrementally increasing volume, helps build sender reputation. Tools like Google Postmaster Tools aid in monitoring and assessing sender reputation.

Key findings

  • Email Authentication: Proper configuration of SPF, DKIM, and DMARC is critical for deliverability.
  • Sender Reputation: A positive sender reputation is a major factor in inbox placement.
  • Gradual IP Warm-up: Gradually increasing sending volume helps establish trust with ISPs.
  • Content Quality: High-quality, valuable content and avoiding spam triggers reduces the risk of being marked as spam.
  • List Hygiene: Maintaining a clean email list by removing bounces is important for maintaining a good sender reputation

Key considerations

  • Monitoring: Regularly monitor deliverability metrics and spam complaints to identify and address issues.
  • Engagement: Focus on sending emails to engaged users to improve sender reputation.
  • Avoid Unsolicited Email: Only send emails to users who have explicitly opted in to receive them.
  • Use Google Postmaster Tools: Monitor your sender reputation with Google Postmaster Tools to identify issues.
  • Implement valuable content: Create valuable content to improve engagement and sender reputation.
Technical article

Documentation from SparkPost Documentation shares that IP warm-up involves gradually increasing sending volume to establish a positive sender reputation. Start with small volumes to engaged users and slowly increase volume over time, monitoring deliverability metrics.

June 2021 - SparkPost Documentation
Technical article

Documentation from Postmark says that sender reputation is one of the most important factors in inbox placement. If your sender reputation is bad the mail will go to spam. Use tools like Google Postmaster Tools to get a sense of your reputation. <https://postmarkapp.com/blog/how-to-keep-your-emails-out-of-the-spam-folder>

January 2023 - Postmark
Technical article

Documentation from Microsoft explains that to avoid email going to junk folders, it is important to ensure the sending domain is authenticated, to maintain list hygiene by removing bounces, and to ensure the content is high-quality, valuable and free of spam triggers. <https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/anti-spam-policies-best-practices?view=o365-worldwide>

March 2023 - Microsoft
Technical article

Documentation from Google Workspace Admin Help explains that to improve email deliverability to Gmail, ensure SPF, DKIM, and DMARC are properly set up. Also, avoid sending unsolicited email, maintain a good sending reputation, and monitor spam complaints.

March 2024 - Google Workspace Admin Help