How does sharing IP ranges affect email deliverability and how can I manage IP reputation for different clients?

Summary

Sharing IP ranges can significantly impact email deliverability due to shared IP reputation, where poor sending practices by one sender can negatively affect others. Managing IP reputation for different clients involves strategies like using dedicated IPs for full control and isolating reputation issues, or setting up IP pools and VMTAs to segment clients based on their sending habits, using PowerMTA. Proper IP warming is crucial for gradually building a positive reputation, and tools like Google Postmaster Tools and GlockApps are essential for monitoring IP and domain reputation. Authentication methods such as SPF records, maintaining clean lists, actively addressing blocklisting, and utilizing feedback loops for identifying spam complaints are vital for improving and maintaining sender reputation.

Key findings

  • Shared IP Risk: Sharing IPs leads to shared IP reputation, impacting deliverability based on the program's health.
  • Dedicated IP Benefit: Dedicated IPs offer full control over sending reputation and isolation of reputation issues.
  • Segmentation Strategies: Techniques like IP pools and VMTAs (using PowerMTA) help manage reputation by segmenting clients.
  • IP Warming Necessity: Properly warming up IP addresses is critical for establishing a positive sending reputation.
  • Monitoring Importance: Actively monitoring IP, domain reputation using tools such as Google Postmaster Tools, and GlockApps is crucial for proactive issue detection.
  • Authentication Protocols: Using SPF records and other authentication protocols prevents spoofing and improves deliverability.
  • List Hygiene Significance: Maintaining clean email lists reduces bounce rates and spam complaints, improving sender reputation.
  • Blocklist Management: Quickly addressing blocklisting issues is crucial to minimize damage to deliverability.
  • Feedback Loop Utilization: Utilizing feedback loops (FBLs) helps remove spam complainants and maintain list integrity.

Key considerations

  • Program Health: Consider the overall health of your email program to understand how shared IPs can impact deliverability.
  • Risk of Shared IPs: Acknowledge that even one sender with poor habits affects the deliverability of all using shared IP ranges.
  • Cost of Dedicated IPs: Evaluate the costs and complexity of dedicated IPs against the benefits of reputation control.
  • Warming Schedule Planning: Develop and follow a strict schedule for warming up new IPs to ensure a positive start.
  • Data Monitoring: Implement regular data monitoring and analysis using deliverability tools to identify anomalies.
  • Prompt Reaction: Develop processes for prompt reaction to blacklisting or other reputation-related problems.
  • Testing for Deliverability: Continually test your deliverability

What email marketers say
11Marketer opinions

Sharing IP ranges can significantly affect email deliverability due to shared IP reputation. A sender with poor practices on a shared IP can negatively impact the deliverability of all senders using that IP. Managing IP reputation involves strategies like separating clients with different sending habits onto different IPs, setting up pools and VMTA's, and warming up IPs to gradually build reputation. Monitoring IP reputation through tools like Google Postmaster Tools, authenticating emails, maintaining clean lists, and promptly addressing blocklistings are also essential.

Key opinions

  • Shared IP Reputation: Sharing IPs means sharing IP reputation, impacting deliverability.
  • Client Segmentation: Separating clients with different sending habits onto different IPs is a common strategy.
  • IP Pools and VMTA's: PowerMTA can be used to set up IP pools and VMTA's to manage different client reputations.
  • Monitoring is Crucial: Actively monitoring IP reputation is essential for identifying and addressing deliverability issues.
  • Improve Sender Reputation: Improving sender reputation involves authentication, list maintenance, and avoiding spam triggers.
  • IP Blocklists: Being on an IP blocklist is detrimental and requires immediate action.
  • Deliverability Testing: Regular testing helps identify deliverability problems.
  • Feedback Loops: Utilizing FBLs helps identify and remove spammers from list improving reputation.

Key considerations

  • Program Health: The healthiness of your entire email program affects the impact of shared IPs on deliverability.
  • Low-Performing Pools: Ensure the lowest performing IP pool doesn't negatively impact others.
  • Authentication: Implement email authentication protocols (SPF, DKIM, DMARC).
  • List Hygiene: Maintain clean email lists to minimize bounce rates and spam complaints.
  • Proactive Monitoring: Regularly check IP reputation and deliverability metrics.
  • IP Warming: Implement IP warming strategy for new IPs
Marketer view

Marketer from Email Geeks explains that any attribute of an email has some type of reputation tied to it. Sharing IPs means sharing IP reputation between email streams, impacting deliverability depending on the program's health.

August 2024 - Email Geeks
Marketer view

Email marketer from Mailjet shares that sharing IP addresses can negatively impact deliverability if one sender on the IP has poor sending practices. Maintaining a good IP reputation is crucial for ensuring emails reach the inbox.

March 2022 - Mailjet
Marketer view

Email marketer from StackOverflow explains that using multiple IPs can help segment email traffic based on reputation. If one IP gets blocked, it doesn't affect emails sent from other IPs.

December 2024 - StackOverflow
Marketer view

Email marketer from GlockApps shares that regularly testing deliverability with a tool like GlockApps helps identify potential problems with IP reputation and placement in different inboxes.

February 2025 - GlockApps
Marketer view

Email marketer from an Email Marketing Forum explains that being on an IP blocklist is detrimental to deliverability and requires immediate action, such as contacting the blocklist provider and addressing the issues that caused the listing.

August 2021 - Email Marketing Forum
Marketer view

Email marketer from Reddit explains that separating clients with different sending habits onto different IP addresses is a common strategy. This prevents a low-quality sender from tanking the IP reputation for everyone.

April 2022 - Reddit
Marketer view

Marketer from Email Geeks shares that you can set up pools and vmta's in PowerMTA to manage different client reputations by using different IP ranges. However, ensure the lowest performing IP pool doesn't negatively impact the deliverability of others in that pool. You can also adjust connection and throughput settings for each pool.

February 2024 - Email Geeks
Marketer view

Email marketer from SuperOffice shares that improving sender reputation involves several steps, including authenticating emails, maintaining clean lists, and avoiding spam triggers.

February 2022 - SuperOffice
Marketer view

Email marketer from Litmus explains that actively monitoring IP reputation using tools like Google Postmaster Tools is essential for identifying and addressing deliverability issues promptly.

May 2022 - Litmus
Marketer view

Email marketer from Validity (formerly ReturnPath) explains that utilizing feedback loops (FBLs) allows you to receive notifications when recipients mark your emails as spam, enabling you to remove those recipients from your list and improve your sender reputation.

May 2021 - Validity
Marketer view

Email marketer from Email on Acid shares that a good sender reputation is critical for email deliverability, including IP reputation. Factors like spam complaints and bounce rates contribute to this reputation.

September 2023 - Email on Acid

What the experts say
3Expert opinions

Experts emphasize that IP address reputation significantly affects email deliverability. Using a dedicated IP address offers control over your reputation, which is crucial when managing clients with varying sending practices. Warming up new IPs gradually builds a positive reputation, while sudden large sending volumes can negatively impact your IP reputation. Key factors contributing to reputation include sending volume, spam complaints, and engagement metrics.

Key opinions

  • Dedicated IP Control: Dedicated IPs provide control over email reputation, affecting deliverability.
  • IP Warming Importance: Proper IP warming gradually builds a positive reputation.
  • Reputation Factors: Sending volume, spam complaints, and engagement metrics influence IP reputation.

Key considerations

  • Dedicated IP Cost: Consider the cost and technical requirements of managing dedicated IPs.
  • Gradual Sending Volume: Avoid sudden large sending volumes with new IPs to prevent reputation damage.
  • Engagement Metrics: Monitor engagement metrics (opens, clicks) to identify potential deliverability issues.
Expert view

Expert from Word to the Wise highlights that the reputation of your sending IP address significantly impacts email deliverability. Factors contributing to reputation include sending volume, spam complaints, and engagement metrics.

May 2024 - Word to the Wise
Expert view

Expert from Word to the Wise, Laura Atkins, shares the importance of warming up new IPs. Proper IP warming gradually builds a positive reputation, which impacts deliverability. Sudden large sending volumes can negatively impact your IP reputation. Although this doesn't 100% answer the prompt it is closely linked.

November 2022 - Word to the Wise
Expert view

Expert from Spam Resource explains that using a dedicated IP address gives you control over your email reputation, which directly affects deliverability. This control is crucial when managing different clients with varying sending practices.

October 2021 - Spam Resource

What the documentation says
4Technical articles

Technical documentation emphasizes the importance of managing IP reputation for email deliverability. Using dedicated IP addresses gives full control and allows for isolating reputation issues. Warming up IPs gradually is crucial for establishing a good reputation and preventing deliverability problems. Services like Google Postmaster Tools provide data on sending reputation to help improve deliverability. Implementing SPF records is vital for email authentication, preventing spoofing, and enhancing deliverability.

Key findings

  • Dedicated IP Control: Dedicated IPs provide full control over sending reputation.
  • IP Warming: Properly warming up IPs is crucial for establishing a good reputation.
  • Reputation Monitoring: Tools like Google Postmaster Tools provide data to monitor and improve sending reputation.
  • SPF Authentication: SPF records are crucial for email authentication and preventing spoofing.

Key considerations

  • IP Isolation Benefits: Consider the benefits of isolating different clients on separate IPs for reputation management.
  • Warming Schedule: Develop a gradual IP warming schedule to avoid deliverability issues.
  • Data Analysis: Regularly analyze Google Postmaster Tools data to identify and address deliverability problems.
  • SPF Record Setup: Ensure SPF records are properly configured to authorize sending mail servers.
Technical article

Documentation from SparkPost explains that properly warming up IP addresses by gradually increasing sending volume is important for establishing a good IP reputation. Sending too much email too quickly can negatively affect deliverability.

March 2023 - SparkPost
Technical article

Documentation from SendGrid explains that using dedicated IP addresses gives you full control over your sending reputation, which impacts deliverability. Separating clients by IP allows isolating reputation issues.

April 2022 - SendGrid
Technical article

Documentation from Google Postmaster Tools explains that its service provides data about your sending reputation including spam rate, IP reputation, and domain reputation to help improve deliverability.

March 2023 - Google
Technical article

Documentation from RFC explains that using SPF records is crucial for email authentication, as they specify which mail servers are authorized to send emails on behalf of your domain, preventing spoofing and improving deliverability.

January 2022 - RFC