Why is my Gmail domain reputation dropping from confirmation emails and how can I fix it?

Summary

A dropping Gmail domain reputation from confirmation emails is a complex issue with multiple contributing factors. Key causes include subscription bombing, low engagement, content triggering spam filters, poor list hygiene, and inadequate email authentication (SPF, DKIM, DMARC). Sending unwanted mail, high bounce rates, and the segregation of transactional email, especially COI emails, can also negatively impact reputation. Solutions involve implementing robust signup protections (CAPTCHAs, hidden fields, confirmed opt-in), maintaining thorough audit trails, warming up IP addresses, segmenting email lists, consistently sending valuable content, monitoring feedback loops with Google Postmaster Tools, and focusing on delivering relevant and wanted mail.

Key findings

  • Authentication is Key: Proper email authentication (SPF, DKIM, DMARC) is critical to verifying sender identity and preventing spoofing and phishing attacks, which directly impacts domain reputation.
  • Subscription Bombing Impacts: Confirmation emails are frequently targeted by subscription bombing, leading to spam complaints and damage to sender reputation.
  • Engagement Matters: Low engagement with confirmation emails can cause Gmail to flag them as spam, highlighting the need for personalization, relevant content, and enticing subject lines.
  • List Hygiene is Critical: Maintaining a clean and engaged email list is vital, as high bounce rates, spam complaints, and unengaged recipients significantly degrade sender reputation.
  • Segregation of Transactional Mail Can Backfire: Segregating transactional emails, particularly COI, can isolate negative reputation, prevent good reputation from marketing mail to dilute it, and raise suspicions due to a lack of 'repeat' mail.

Key considerations

  • Implement Signup Protections: Utilize tools like CAPTCHAs, hidden fields, and confirmed opt-in (COI) to prevent fraudulent signups and ensure only legitimate users receive confirmation emails.
  • Monitor Performance with Postmaster Tools: Regularly monitor Google Postmaster Tools to gain insights into deliverability metrics, spam rates, and domain reputation, enabling timely intervention and optimization.
  • Warm Up New IPs/Domains: When starting with a new IP address or domain, gradually warm up the sending volume to establish a positive reputation with Gmail and avoid being flagged as spam.
  • Review and Audit Signup Sources: Thoroughly review and audit signup sources to identify and mitigate potential instances of list bombing or fraudulent activity.
  • Continuously Optimize Content and Engagement: Continuously optimize the content and subject lines of confirmation emails to increase engagement, reduce spam complaints, and ensure they provide value to recipients.

What email marketers say
11Marketer opinions

Several factors contribute to a dropping Gmail domain reputation due to confirmation emails. These include low engagement, content triggering spam filters, poor list hygiene, and lack of proper email authentication (SPF, DKIM, DMARC). High spam complaint rates, bounces, and the possibility of list bombing (where spammers sign up many addresses) also negatively impact reputation. Solutions involve implementing CAPTCHAs and hidden fields, warming up IP addresses, segmenting email lists, monitoring Google Postmaster Tools, personalizing emails, and separating transactional from marketing email reputations.

Key opinions

  • Engagement Matters: Low engagement with confirmation emails can cause Gmail to filter them as spam, suggesting a need for personalization and better subject lines.
  • Authentication is Crucial: Proper email authentication (SPF, DKIM, DMARC) is essential to verify your identity and prevent emails from being marked as spam.
  • List Hygiene: Maintaining a clean email list by removing inactive subscribers and addressing bounces is critical for improving sender reputation.
  • Monitor Performance: Regularly monitoring Google Postmaster Tools and other feedback loops allows for prompt identification and resolution of deliverability issues.
  • Bogus Signups: Hidden fields and CAPTCHAs are methods used to filter out bogus signups to prevent spam filters.

Key considerations

  • Volume: Emails immediately after opt-in are sometimes going to have higher negative KPIs. Consider the overall volume of emails sent.
  • Content: Content within confirmation emails should be relevant and avoid spam trigger words to improve inbox placement.
  • Transactional Reputation: Consider monitoring your transactional email reputation separately from marketing emails, possibly using dedicated IPs.
  • IP Warmup: Warm up your IP address to improve reputation.
  • Engagement Data: Check your domain against blocklists and look at your engagement data. High unsubscribe/spam rates mean it might be time to remove unengaged recipients.
Marketer view

Email marketer from Klenty says to check your domain against blocklists, fix your DNS records and look at your engagement data (opens, clicks etc). High unsubscribe/spam rates are bad and it might be time to remove unengaged recipients.

February 2023 - Klenty
Marketer view

Email marketer from StackExchange says that confirmation emails may land in spam due to content triggers or missing authentication. Ensuring proper SPF and DKIM records, along with providing clear unsubscribe options, can help improve deliverability. Also, consider the frequency and relevance of the confirmation emails to avoid being flagged as spam.

October 2024 - StackExchange
Marketer view

Email marketer from Reddit shares that domain reputation is affected by various factors, including spam complaints, bounce rates, and engagement metrics. To improve it, focus on list hygiene, sending relevant content, and ensuring proper authentication. Regularly monitoring feedback loops and addressing any issues promptly can help rebuild trust with Gmail.

May 2021 - Reddit
Marketer view

Email marketer from ActiveCampaign Blog suggests monitoring your transactional email reputation separately from your marketing emails. Use dedicated IPs for transactional emails, ensure proper authentication, and track bounce rates and spam complaints to identify and address issues quickly. Keeping transactional emails focused and relevant is crucial.

January 2023 - ActiveCampaign Blog
Marketer view

Email marketer from Mailjet Blog shares that improving sender reputation involves consistently sending valuable content, maintaining a clean email list by removing inactive subscribers, authenticating emails with SPF, DKIM, and DMARC, and monitoring feedback loops to address issues promptly. Focusing on engagement and avoiding spam triggers are key to rebuilding trust with Gmail.

January 2025 - Mailjet Blog
Marketer view

Email Marketer from Sender.net says to warm up your IP address, authenticate emails, maintain consistent sending volume, segment your list and monitor sending reputation using tools such as Google Postmaster Tools.

July 2024 - Sender.net
Marketer view

Email marketer from Reddit suggests that confirmation emails might be caught in Gmail's spam filters due to a lack of engagement or perceived low value. Ensuring clear opt-in processes, personalizing the emails, and testing different subject lines can help improve inbox placement. Also, monitor Google Postmaster Tools for insights into spam rates.

April 2022 - Reddit
Marketer view

Email Marketer from Email Geeks shares that emails immediately after opt-in are sometimes going to have higher negative KPIs and says to consider volume.

September 2022 - Email Geeks
Marketer view

Email Marketer from Email Geeks says that hidden fields and CAPTCHAs are typical methods used to filter out bogus signups.

February 2024 - Email Geeks
Marketer view

Email marketer from Litmus says to ensure email authentication as Gmail and other providers use this to verify you are who you say you are.

March 2025 - Litmus
Marketer view

Email marketer from Gmass shares a blog on improving low open rates. Suggesting that email marketers should avoid spam trigger words, segment lists and send relevant content. Plus send from a dedicated IP address.

January 2025 - Gmass

What the experts say
11Expert opinions

A dropping Gmail domain reputation from confirmation emails is often due to issues like subscription bombing, poor email deliverability related to transactional mail segregation, and insufficient traffic to establish a clean subdomain reputation. Experts recommend maintaining audit trails, using COI infrastructure and CAPTCHAs to prevent fraudulent signups, and reviewing signup sources and IP addresses to mitigate list bombing. The lack of good reputation due to low volume with new IPs/domains can also lead to throttling or spam placement, and simply segregating transactional mail may do more harm than good to your over all domain reputation.

Key opinions

  • Subscription Bombing: Confirmation emails are prime targets for subscription bombing, negatively impacting sender reputation through spam traps and complaints.
  • Segregation Issues: Segregating transactional mail, particularly COI emails, can harm deliverability because it isolates potentially negative reputation and lacks positive influence from broader mailstreams.
  • New IP/Domain Volume: Sending high volumes from new IPs and domains without establishing a positive reputation results in throttling or spam placement by Gmail.
  • Fraudulent Signups: Subscription requests from automation can lead to confirmation emails being sent to users who didn't request them which has a negative impact.
  • Domain Repair: Subdomain reputation cannot be repaired with current low volume. Segregating can make your mailstream look worse.

Key considerations

  • Audit Trails: Maintaining detailed audit trails of signups can help identify and prevent fraudulent activity.
  • COI Infrastructure: Using ESP's COI infrastructure and tools like Zerocaptcha can prevent fraudulent signups and improve deliverability.
  • IP Reputation: Consider IP reputation of sign-ups
  • Review Signup Sources: Regularly review signup sources and IP addresses to mitigate the impact of list bombing.
  • Traffic and Mailstream: There's no repeat mail on that domain, which is suspicious.
Expert view

Expert from Word to the Wise explains you shouldn't send a huge amount of volume when starting out with a new IP and domain because you don't have a reputation and Gmail doesn't know you. If you are doing this, Gmail will throttle you or send you to spam.

June 2024 - Word to the Wise
Expert view

Expert from Spam Resource explains that confirmation emails are often targets of list bombing, where spammers sign up many addresses to a list. If you send confirmation emails to these addresses, and some are spam traps or complain, it will hurt your sending reputation. He recommends reviewing sign up sources and IP addresses to reduce this.

June 2021 - Spam Resource
Expert view

Expert from Email Geeks shares that many folks use COI to avoid bad signups leading to poor reputation. By segregating it, all the bad traffic is on one subdomain.

October 2023 - Email Geeks
Expert view

Expert from Email Geeks recommends maintaining an audit trail of signups, including timestamps, peer IP addresses, signed-up emails, and metadata like the referer header, to identify potentially fraudulent activity.

June 2023 - Email Geeks
Expert view

Expert from Email Geeks shares they don't think the subdomain rep can be repaired with the traffic and it's not quite clean enough.

February 2023 - Email Geeks
Expert view

Expert from Email Geeks shares if transactional mail is the COI mail then it will look suspicious because there is no repeat mail on that domain.

August 2023 - Email Geeks
Expert view

Expert from Email Geeks shares there is no generic 'how to do this' and can only offer a "Here's why folks might be giving you fake data and here are some strategies."

September 2024 - Email Geeks
Expert view

Expert from Email Geeks explains that reputation isn't always directly correlated with delivery, and low open rates might indicate spam placement or Google not pre-fetching mail.

April 2022 - Email Geeks
Expert view

Expert from Email Geeks suggests the possibility of subscription bombing or other automated sign-up requests leading to confirmation emails being sent to users who didn't request them.

August 2021 - Email Geeks
Expert view

Expert from Email Geeks suggests using the ESP's COI (Confirmed Opt-In) infrastructure and tools like Zerocaptcha to help prevent fraudulent signups and improve email deliverability.

June 2021 - Email Geeks
Expert view

Expert from Email Geeks suggests segregating transactional mail can hurt deliverability because the good reputation isn't helping with the iffy transactional mail.

November 2021 - Email Geeks

What the documentation says
4Technical articles

Gmail domain reputation drops due to low sender reputation, which is influenced by spam complaints, sending unwanted mail, poor authentication practices, high bounce rates, and poor list hygiene. Implementing proper authentication (SPF, DKIM, DMARC) is crucial to verify your domain and prevent malicious actors from sending messages on your behalf. Regular list cleaning, implementing confirmed opt-in (COI), and reducing spam rates also help improve domain reputation and deliverability. Properly implemented DMARC will protect against email spoofing and phishing attacks.

Key findings

  • Sender Reputation: Low sender reputation leads to emails being marked as spam or rejected by Gmail.
  • Authentication: Proper authentication practices (SPF, DKIM, DMARC) are essential for domain verification and prevent spoofing.
  • List Hygiene: High bounce rates and poor list hygiene negatively impact domain reputation.
  • Spam Complaints: Spam complaints are a major factor influencing sender reputation.
  • Sending Unwanted Mail: Sending unwanted mail can harm domain reputation.

Key considerations

  • Implement SPF: Implement SPF records to authorize specific servers to send emails on behalf of your domain.
  • Implement DKIM: Consider DKIM to increase domain deliverability
  • Implement DMARC: Implement DMARC to protect your domain from email spoofing and phishing attacks.
  • Regular Cleaning: Regularly clean your email list to remove inactive subscribers and reduce bounce rates.
  • COI Implementation: Implement confirmed opt-in (COI) to ensure recipients want to receive your emails.
Technical article

Documentation from SparkPost explains that domain reputation is a critical factor in email deliverability. Issues arise from high bounce rates, spam complaints, and poor list hygiene. Solutions include implementing confirmed opt-in (COI), regularly cleaning the email list, and ensuring emails are properly authenticated to avoid being flagged as spam.

August 2024 - SparkPost Documentation
Technical article

Documentation from RFC-Editor explains that SPF records allow you to authorize specific servers to send emails on behalf of your domain. SPF records assist in helping prevent malicious actors from sending messages on your behalf.

June 2022 - RFC-Editor
Technical article

Documentation from Google Postmaster Tools Help explains that a low sender reputation can cause emails to be marked as spam or rejected. This is influenced by factors such as spam complaints, sending unwanted mail, and authentication practices. To fix this, ensure proper authentication (SPF, DKIM, DMARC), send wanted mail, and reduce spam rates.

May 2021 - Google Postmaster Tools Help
Technical article

Documentation from DMARC.org explains that implementing DMARC helps protect your domain from email spoofing and phishing attacks. Proper implementation involves setting up SPF and DKIM, publishing a DMARC record, and monitoring reports to identify and address any authentication issues. This can improve your domain reputation with Gmail.

November 2024 - DMARC.org