Why have email open and CTR rates decreased after switching to Omnisend and emails are going to spam?

Summary

Decreased email open and CTR rates, coupled with emails landing in spam after switching to Omnisend, are multifaceted issues. Core contributing factors span improper IP warmup, authentication misconfigurations (SPF, DKIM, DMARC), poor list hygiene, low sender reputation, rapid sending volume increases, low subscriber engagement, and content issues. The type of IP (dedicated vs. shared) can also influence deliverability. Experts recommend verifying open rate data, identifying problematic ISPs, checking authentication configurations, ensuring link domain alignment, and improving subscriber engagement. Following deliverability best practices, such as domain authentication, IP warming, and maintaining a clean email list, is vital. Tools like Google Postmaster Tools and aboutmy.email can help diagnose issues. Addressing platform-specific problems using Microsoft's SNDS and JMRP is also crucial for Outlook/Hotmail.

Key findings

  • IP Warmup: Insufficient or improper IP warmup after switching ESPs is a major contributor to deliverability issues.
  • Authentication: Incorrect or missing SPF, DKIM, and DMARC records are a primary cause of emails being flagged as spam.
  • List Hygiene: Poor list hygiene and sending to unengaged subscribers negatively impact sender reputation.
  • Sender Reputation: A low sender reputation results in lower open and CTR rates and increased likelihood of emails landing in spam.
  • Sending Volume: Rapidly increasing sending volume after switching ESPs can trigger spam filters.
  • Engagement: Low subscriber engagement rates indicate that emails may not be wanted.
  • Domain Alignment: Using different domain links to what the sender has can trigger spam filters.

Key considerations

  • IP Warmup Strategy: Develop and execute a gradual IP warmup strategy to build a positive sender reputation with Omnisend.
  • Authentication Verification: Verify and correct SPF, DKIM, and DMARC records to ensure proper email authentication.
  • List Cleaning: Implement a regular list cleaning process to remove unengaged subscribers and maintain a healthy email list.
  • Content Review: Review email content for spam trigger words and phrases, and adjust as needed.
  • Engagement Monitoring: Monitor subscriber engagement metrics (opens, clicks) and segment lists based on engagement levels.
  • Sender Reputation Monitoring: Utilize Google Postmaster Tools and other services to monitor sender reputation and identify potential issues.
  • ISP Troubleshooting: Investigate which ISPs are delivering emails to spam folders and tailor strategies accordingly.
  • Platform Specific Actions: Implement required changes in SNDS and JMRP if you are sending to outlook or hotmail accounts.
  • Data Verification: Verify the open rate data is accurate as it could be an ESP reporting issue.

What email marketers say
11Marketer opinions

Decreased email open and CTR rates, along with emails landing in spam after switching to Omnisend, can stem from a variety of deliverability issues. Key contributing factors include improper IP warmup, changes to IP reputation, incorrect email authentication settings (SPF, DKIM, DMARC), poor list hygiene, use of spam trigger words, low sender reputation, rapid sending volume increases, and low subscriber engagement. Whether using a dedicated or shared IP can also play a part. Addressing these areas is critical for improving email deliverability.

Key opinions

  • IP Warmup: Improper or lack of IP warmup after switching ESPs significantly impacts deliverability.
  • Authentication: Incorrect or missing SPF, DKIM, and DMARC records lead to emails being flagged as spam.
  • List Hygiene: Poor list hygiene and sending to unengaged subscribers harm sender reputation.
  • Sender Reputation: Low sender reputation results in lower open and CTR rates and increased spam placement.
  • Sending Volume: Rapidly increasing sending volume after switching can trigger spam filters.
  • IP Type: Type of IP (dedicated vs. shared) can impact deliverability.

Key considerations

  • IP Warmup Strategy: Develop and execute a gradual IP warmup strategy to establish a positive sender reputation with Omnisend.
  • Authentication Verification: Thoroughly verify and correct SPF, DKIM, and DMARC records to ensure proper email authentication.
  • List Cleaning: Implement a regular list cleaning process to remove unengaged subscribers and maintain a healthy email list.
  • Content Review: Review email content for spam trigger words and phrases and adjust accordingly.
  • Engagement Monitoring: Monitor subscriber engagement metrics (opens, clicks) and segment lists based on engagement levels.
  • Sender Reputation Monitoring: Use tools like Google Postmaster Tools to monitor sender reputation and identify potential issues.
Marketer view

Email marketer from HubSpot explains that having a dedicated IP could impact delivery as it is 'cold' and needs to be warmed up. Conversely they suggest that if you have a shared IP then another user could have damaged the reputation which is now hurting the sender.

August 2022 - HubSpot
Marketer view

Email marketer from EmailVendorSelection.com responds that an improper IP warmup can lead to deliverability issues. Gradually increasing sending volume and monitoring engagement metrics are essential to establish a positive sender reputation with the new ESP.

October 2024 - EmailVendorSelection.com
Marketer view

Email marketer from Email Geeks shares that if the sender changed a lot (domains, IPs, etc.) and didn't do a proper cut-over/warmup, then that might contribute to the low open and CTR rates.

November 2023 - Email Geeks
Marketer view

Email marketer from Gmass shares that sending too many emails too quickly after migrating to a new ESP can trigger spam filters. Gradually increasing sending volume allows you to build a positive sending reputation with the new ESP.

March 2023 - Gmass
Marketer view

Email marketer from Quora shares that using spam trigger words or phrases in your email content can cause emails to be filtered as spam. Reviewing your email content and avoiding such triggers can improve deliverability.

February 2025 - Quora
Marketer view

Email marketer from Email Geeks asks if the sender is using shared or dedicated IPs.

October 2023 - Email Geeks
Marketer view

Email marketer from Reddit explains that switching ESPs can impact IP reputation, especially if the new IP address has a poor sending history. This can cause emails to land in spam, leading to lower open and CTR rates.

July 2023 - Reddit
Marketer view

Email marketer from Customer.io shares that low engagement (low open and CTR rates) sends signals to ISPs that your mail may not be wanted. Segmenting and sending to engaged users can improve results.

April 2022 - Customer.io
Marketer view

Email marketer from Stack Overflow shares that incorrect or missing email authentication records (SPF, DKIM, DMARC) are a common cause of deliverability problems after migrating to a new ESP. Verifying these settings is crucial for ensuring emails are properly authenticated and not flagged as spam.

August 2023 - Stack Overflow
Marketer view

Email marketer from Litmus answers that your Sender Reputation is an indication of your trustworthiness as a sender, which Email Service Providers (ESPs) use to assess the quality of your emails. Poor sender reputation can significantly impact deliverability and lead to lower open and CTR rates.

January 2024 - Litmus
Marketer view

Email marketer from Email Geeks forum responds that poor list hygiene and sending to unengaged subscribers can negatively impact sender reputation and cause emails to go to spam. Regularly cleaning your email list and removing inactive subscribers is essential for maintaining good deliverability.

April 2023 - Email Geeks

What the experts say
6Expert opinions

Following a switch to Omnisend, declining email open and click-through rates, coupled with emails being directed to spam, necessitate a thorough investigation. Experts recommend verifying the accuracy of reported open rates and identifying whether spam placement is the primary issue. Troubleshooting involves pinpointing problematic ISPs, checking email authentication configurations using tools like aboutmy.email, and ensuring link domains align with the sender's. Core contributing factors encompass low engagement, authentication misconfigurations, spam complaints, invalid addresses, and discrepancies in content or link domains.

Key opinions

  • Open Rate Accuracy: The decline in open rates may be due to measurement discrepancies between ESPs rather than actual deliverability issues.
  • ISP Identification: Identifying the specific ISPs sending emails to spam is crucial for targeted troubleshooting.
  • Authentication Verification: Incorrectly configured or missing SPF, DKIM, and DMARC records post-migration commonly lead to deliverability problems.
  • Link Domain Alignment: Link domains not matching the sender's domain can trigger spam filters.
  • Engagement Impact: Low engagement rates contribute to deliverability issues.

Key considerations

  • Verify Open Rate Data: Validate open rate data to determine if the decline is real or an artifact of the new ESP's reporting methods.
  • Investigate Spam Placement: Determine which ISPs are delivering emails to spam folders.
  • Implement Authentication Checks: Use tools like aboutmy.email to verify the correct configuration of SPF, DKIM, and DMARC records.
  • Review Link Domains: Ensure all links in emails use the sender's domain to avoid triggering spam filters.
  • Improve Engagement: Implement strategies to improve subscriber engagement and reduce spam complaints.
Expert view

Expert from Email Geeks shares that tracking down which ISP / mailbox provider is sending to spam will help guide next steps.

April 2021 - Email Geeks
Expert view

Expert from Word to the Wise explains that deliverability issues are often due to factors like low engagement (people not opening or clicking), authentication problems (SPF, DKIM, DMARC misconfiguration after a platform switch), spam complaints, or sending to invalid addresses. Additionally, changes in content and link domains can impact filter decisions.

December 2023 - Word to the Wise
Expert view

Expert from Email Geeks suggests sending mail to aboutmy.email to check if all of the sender's authentication is correctly configured.

July 2024 - Email Geeks
Expert view

Expert from Spam Resource explains that setting up email authentication protocols is essential for identifying the source of mailings and helps mailbox providers determine sender reputation. He shares that issues may arise post platform migration if authentication records are incorrect or missing.

November 2024 - Spam Resource
Expert view

Expert from Email Geeks asks if the decrease in open rates is real or if the ESPs are modifying the data. If real, is it due to emails going to the spam folder or something else?

November 2021 - Email Geeks
Expert view

Expert from Email Geeks explains to check the links in the aboutmy.email report. If the link domains are not the senders domain, then that's a possible filter target as well.

December 2023 - Email Geeks

What the documentation says
5Technical articles

Decreased email open and CTR rates after switching to Omnisend, with emails landing in spam, often result from neglecting key deliverability practices. Documentation highlights the importance of domain authentication (SPF, DKIM, DMARC), IP warming, and maintaining a clean email list. Utilizing tools like Google Postmaster Tools is vital for monitoring domain reputation and identifying deliverability issues. Properly configuring SPF records and aligning with DMARC policies ensures emails are delivered correctly. If facing issues with Outlook or Hotmail, Microsoft recommends using SNDS and JMRP and joining their sender support program.

Key findings

  • Authentication Importance: Correctly configuring SPF, DKIM, and DMARC is essential for email deliverability.
  • IP Warmup Critical: Warming up the IP address is vital to avoid spam filters and maintain a good sender reputation after platform migration.
  • List Hygiene Key: Maintaining a clean email list significantly improves deliverability and sender reputation.
  • Monitoring Tools Essential: Tools like Google Postmaster Tools provide valuable insights into domain reputation and deliverability metrics.
  • DMARC Alignment Necessary: Aligning with DMARC policies is crucial for ensuring email delivery.

Key considerations

  • Implement Authentication: Implement and regularly check SPF, DKIM, and DMARC settings.
  • Conduct IP Warmup: Plan and execute a gradual IP warmup strategy.
  • Practice List Hygiene: Regularly clean and segment email lists.
  • Monitor Reputation: Utilize Google Postmaster Tools for ongoing monitoring of domain reputation.
  • Address Platform-Specific Issues: Use Microsoft's SNDS and JMRP for Outlook/Hotmail issues.
Technical article

Documentation from RFC explains that an SPF record must be properly configured for your sending domain to authorize the new ESP to send emails on your behalf. An incorrect or missing SPF record can cause emails to fail SPF checks and be marked as spam.

October 2024 - RFC
Technical article

Documentation from Omnisend Help Center shares that following deliverability best practices, such as authenticating your domain (SPF, DKIM, DMARC), warming up your IP address, and maintaining a clean email list, is crucial after switching platforms to avoid spam filters and maintain good sender reputation.

March 2025 - Omnisend Help Center
Technical article

Documentation from Mailchimp answers that DMARC policies set by recipient domains can affect whether emails are delivered, especially if SPF and DKIM records are not properly configured. Ensure your DMARC policy is aligned with your email authentication setup.

August 2021 - Mailchimp
Technical article

Documentation from Microsoft shares using SNDS and JMRP if you are experiencing issues sending to Outlook or Hotmail. It also recommends joining their sender support program.

September 2022 - Microsoft
Technical article

Documentation from Google explains that Google Postmaster Tools can provide insights into your domain's reputation, spam rate, and other deliverability metrics. Monitoring these metrics can help identify and address issues that may be causing emails to land in spam after switching to a new ESP.

July 2024 - Google