Why are my dedicated IPs blocked and how can I fix it?

Summary

Dedicated IPs get blocked primarily due to poor IP reputation and sending practices. Key factors contributing to this include compromised accounts, irregular sending patterns, insufficient IP warm-up, sending to invalid addresses, high spam complaints, exceeding spam thresholds, sending unsolicited emails, poor list hygiene, sudden volume spikes, low sender scores, missing/incorrect reverse DNS (PTR) records, inadequate email authentication (SPF, DKIM, DMARC), unmonitored feedback loops, blacklisting, and domain reputation issues. Solutions involve monitoring IP reputation via tools like SNDS, Sender Score, and GlockApps; properly warming up IPs; cleaning email lists; gradually increasing sending volume; setting up authentication protocols; monitoring feedback loops; addressing blacklist listings; ensuring correct IP assignment and rDNS; and considering domain reputation defense strategies.

Key findings

  • Reputation Monitoring: Regular monitoring of IP reputation is critical using tools from Microsoft (SNDS), Google (Postmaster Tools), Sender Score, and GlockApps.
  • IP Warm-up: Properly warming up new IPs by gradually increasing volume and engaging most active users establishes a positive sending history.
  • List Hygiene: Maintaining a clean list through double opt-in and removing unengaged subscribers prevents spam complaints and bounces.
  • Authentication: Correct setup and validation of SPF, DKIM, and DMARC are essential for establishing trust with receiving mail servers.
  • Feedback Loops: Monitoring and acting upon feedback loops allows quick removal of complainers and reduces spam complaints.
  • rDNS Configuration: Correctly configured reverse DNS (PTR) records help mail servers verify the sending IP's identity.
  • Domain Reputation: Domain reputation and age impact IP deliverability, and subdomain delegation with reputation defense can mitigate problems.
  • Volume Control: Avoid sudden spikes in sending volume that can trigger spam filters and negatively impact IP reputation.

Key considerations

  • Compromised Accounts: Monitor for and address any compromised accounts that could be sending spam.
  • Industry Restrictions: Certain industries may face deliverability challenges due to data practices and may not qualify for some certifications.
  • SNDS Alignment: Compare sending volumes with SNDS data to identify discrepancies and potential problems.
  • Data Sourcing: Understand how your recipient data was acquired and ensure compliance with consent requirements.
  • Blacklist Monitoring: Proactively monitor blacklist status and take swift action to address any listings.
  • Sending Consistency: Maintain consistent sending patterns to avoid raising suspicion with receiving mail servers.
  • ReturnPath Certification: Consider ReturnPath certification if eligible and relevant to your sending practices.
  • Long Term Strategy: Deliverability issues are generally longer term reputation problems which require long term strategies.

What email marketers say
16Marketer opinions

Dedicated IPs get blocked for various reasons, primarily related to IP reputation and sending practices. Key issues include compromised accounts, irregular sending patterns, insufficient IP warm-up, poor list hygiene (sending to unengaged users), sudden spikes in sending volume, a low sender score, missing or incorrect reverse DNS records, improper email authentication setup (SPF, DKIM, DMARC), not monitoring feedback loops, or being blacklisted. Fixing these issues involves monitoring IP reputation (using tools like SNDS, Sender Score, GlockApps), properly warming up IPs, cleaning email lists, gradually increasing sending volume, configuring authentication protocols, monitoring feedback loops, and addressing blacklist listings.

Key opinions

  • Reputation Monitoring: Regularly monitor your IP's reputation using tools like SNDS, Sender Score, and GlockApps to identify issues early.
  • IP Warm-up: Properly warm up new dedicated IPs by gradually increasing sending volume over several weeks to build a positive reputation.
  • List Hygiene: Maintain a clean email list by removing inactive subscribers and using double opt-in to prevent high bounce rates and spam complaints.
  • Authentication: Ensure proper configuration of SPF, DKIM, and DMARC to authenticate your emails and improve deliverability.
  • Feedback Loops: Actively monitor feedback loops from ISPs to identify and remove subscribers who mark your emails as spam.
  • Sending Volume: Avoid sudden spikes in sending volume, especially with new IPs, to prevent triggering spam filters.
  • Reverse DNS: Ensure your IP address has a properly configured PTR record that matches your sending domain.

Key considerations

  • Compromised Account: Investigate potential account compromises if you observe irregular sending patterns.
  • Industry Regulations: Certain industries with bad data practices might not be eligible for certain IP programs and certifications.
  • Email Content: Ensure you send valuable content to engaged recipients to maintain a good sending reputation.
  • Blacklist Removal: If blacklisted, identify the specific blacklists and follow their removal process.
  • SNDS Alignment: Ensure your sending volume aligns with what's reported in Microsoft's SNDS to avoid triggering filters.
  • Data Sourcing: Understand where your data is coming from and only mail to recipients that have provided explicit consent.
Marketer view

Email marketer from Reddit shares that sudden spikes in sending volume can trigger spam filters and lead to IP blocking, especially with new dedicated IPs. They recommend gradually increasing sending volume over time and monitoring deliverability metrics closely.

August 2024 - Reddit
Marketer view

Marketer from Email Geeks responds to the user mentioning the possibility of a compromised account or irregular sending pattern based on the bold text provided, and asks about sending frequency and typical volume.

August 2021 - Email Geeks
Marketer view

Email marketer from Litmus answers that improper configuration of email authentication protocols like SPF, DKIM, and DMARC can lead to IP blocking. They recommend setting up these protocols correctly to verify your identity and improve deliverability.

January 2022 - Litmus
Marketer view

Email marketer from an Email Marketing Forum responds that sending to old, unengaged email lists can result in high bounce rates and spam complaints, leading to IP blocking. They suggest cleaning your email list regularly by removing inactive subscribers and using double opt-in for new sign-ups.

June 2024 - Email Marketing Forum
Marketer view

Email marketer from GlockApps explains that being blacklisted by multiple email service providers can lead to IP blocking. They recommend using their tool to monitor your IP's blacklist status and identify specific blacklists to address.

October 2021 - GlockApps
Marketer view

Email marketer from Stack Overflow responds that a missing or incorrect reverse DNS (PTR) record can negatively impact IP reputation and lead to blocking. They advise ensuring that your IP address has a properly configured PTR record that matches your domain name.

February 2024 - Stack Overflow
Marketer view

Marketer from Email Geeks advises to look at the RCPT/DATA columns in SNDS and check if they roughly align with sending volume.

May 2024 - Email Geeks
Marketer view

Email marketer from Sender Score explains that a low sender score indicates poor IP reputation and can lead to blocking. They recommend using their tool to check your IP's reputation and identify issues like spam complaints, blacklisting, or poor sending practices that need to be addressed.

May 2021 - Sender Score
Marketer view

Email marketer from Neil Patel shares that consistently sending valuable content, segmenting your audience, and removing inactive subscribers can improve your IP reputation and prevent blocking. He also emphasizes the importance of warming up your IP address gradually when starting with a new dedicated IP.

June 2024 - Neil Patel
Marketer view

Email marketer from Mailjet Support shares that not properly warming up your dedicated IP address is a common cause of blocking. They recommend starting with a small volume of emails to your most engaged subscribers and gradually increasing the volume over several weeks to build a positive sending reputation.

February 2022 - Mailjet
Marketer view

Marketer from Email Geeks suggests throttling sends and mentions that Returnpath certification is becoming a necessity to avoid issues with Microsoft on dedicated IPs.

July 2021 - Email Geeks
Marketer view

Email marketer from SparkPost explains that not actively monitoring feedback loops (FBLs) from ISPs can lead to IP blocking. They recommend setting up FBLs to identify and remove subscribers who mark your emails as spam.

September 2023 - SparkPost
Marketer view

Marketer from Email Geeks asks if the user launched a new high volume campaign and whether the IPs are sufficiently warmed.

March 2023 - Email Geeks
Marketer view

Marketer from Email Geeks asks if the user has access to SNDS and whether the volumes seen align with what they are sending to MS domains.

May 2023 - Email Geeks
Marketer view

Marketer from Email Geeks, Pablo Martín, recommends checking ReturnPath certification for dedicated IPs and implementing ReturnPath customization on the domain. Dale Langley points out the client's industry (clairvoyance) is unlikely to be eligible for RP certification due to poor data practices and suggests focusing on well-acquired, recently engaged data and reducing the number of IPs.

April 2024 - Email Geeks
Marketer view

Marketer from Email Geeks asks about the type of email/data sourcing and suggests specifying individual IPs in support requests, also asks to check what is says under SNDS when you look at "view IP status".

August 2021 - Email Geeks

What the experts say
2Expert opinions

John Levine from Spam Resource emphasizes the importance of correct IP assignment and valid reverse DNS records, ensuring the IP block is properly registered and the rDNS is set up correctly. Laura Atkins from Word to the Wise points out that domain reputation and age are crucial and can indirectly cause IP deliverability issues, suggesting subdomain delegation with reputation defense as a solution.

Key opinions

  • Proper IP Assignment: Correctly assigning IPs and ensuring valid reverse DNS records are essential for deliverability.
  • Domain Reputation Impact: Domain reputation and age significantly impact IP deliverability.
  • rDNS Configuration: The reverse DNS (rDNS) must be correctly set to point to your sending domain.
  • Subdomain Delegation: Implementing subdomain delegation with reputation defense can help improve domain reputation and IP deliverability.

Key considerations

  • IP Block Registration: Ensure your IP block is properly registered to avoid deliverability issues.
  • Domain Age: Consider the age of your domain as it affects your reputation and overall deliverability.
  • Long-Term Strategy: These are generally long-term reputation problems which require long-term strategies.
Expert view

Expert from Spam Resource, John Levine, explains that assigning IPs correctly and ensuring that you have valid reverse DNS is important. He highlights the need to make sure the IP block is properly registered and the rDNS set correctly to point to your sending domain.

August 2023 - Spam Resource
Expert view

Expert from Word to the Wise, Laura Atkins, answers that domain reputation and domain age is important and can indirectly cause IP deliverability issues. She explains that setting up subdomain delegation with reputation defense can solve the domain issues.

March 2022 - Word to the Wise

What the documentation says
3Technical articles

Microsoft, Google, and Spamhaus documentation points to poor IP reputation as the primary reason for dedicated IPs being blocked. This poor reputation stems from spam complaints, sending to invalid addresses, exceeding spam thresholds, sending unsolicited emails, and poor email authentication practices. Remediation involves joining Microsoft's SNDS, using Google Postmaster Tools, adhering to bulk sender guidelines, understanding and addressing Spamhaus blacklist listings, and generally improving sending practices.

Key findings

  • Poor Reputation: Poor IP reputation is a primary cause of IP blocking.
  • Spam Complaints: High spam complaint rates lead to IP blocking.
  • Invalid Addresses: Sending to invalid or non-existent email addresses negatively impacts IP reputation.
  • Authentication Issues: Poor authentication practices (SPF, DKIM, DMARC) can lead to IP blocking.
  • Blacklisting: Being listed on the Spamhaus blacklist indicates spam activity and causes blocking.
  • Unsolicited Emails: Sending unsolicited commercial emails can cause IP reputation issues and blocking.

Key considerations

  • SNDS Monitoring: Join Microsoft's SNDS to monitor IP reputation and user complaints.
  • Postmaster Tools: Utilize Google Postmaster Tools to monitor IP reputation and adhere to bulk sender guidelines.
  • Spamhaus Listing: If listed on Spamhaus, understand the removal process and address the underlying issues.
  • Bulk Sender Guidelines: Follow Bulk Email Sender Guidelines when sending emails.
  • Review Sending Policy: Understand sending policies for ESP.
Technical article

Documentation from Google Postmaster Tools explains that exceeding spam thresholds, sending unsolicited emails, and having poor authentication practices (SPF, DKIM, DMARC) can lead to IP blocking. They suggest using Postmaster Tools to monitor your IP's reputation and adhere to their bulk sender guidelines to improve deliverability.

September 2024 - Google
Technical article

Documentation from Microsoft explains that poor IP reputation due to spam complaints or sending to invalid addresses can lead to blocking. To fix it, they recommend joining their Smart Network Data Services (SNDS) program to monitor your IP's reputation and user complaints, ensuring you comply with their sending policies.

April 2024 - Microsoft
Technical article

Documentation from Spamhaus answers that being listed on their blacklist indicates that your IP has been associated with spam activity. They explain the removal process and provide resources to identify and address the underlying issues causing the blacklisting.

July 2022 - Spamhaus