How does IP range behavior affect other IPs and domain reputation?

Summary

The collective insights underscore the significant influence of IP range behavior on email deliverability and domain reputation. Poor sending practices from any sender within an IP range, particularly on shared IPs, can negatively impact the reputation of other IPs and the domain. Factors like sending habits, list hygiene, the presence of 'noisy neighbors,' sudden sending volume spikes, and spam complaints all contribute to IP reputation, which directly affects deliverability and inbox placement. Major email providers actively monitor IP addresses and enforce policies to maintain deliverability for their users.

Key findings

  • Shared IP Risk: Shared IPs are vulnerable to the actions of other senders. Poor sending practices by 'noisy neighbors' can negatively impact your own reputation and deliverability.
  • Domain-IP Interdependence: Domain reputation is closely linked to IP reputation. A domain associated with an IP address that has a poor sending history will experience deliverability issues.
  • Poor Practices Impact: Poor sending practices, such as sending to unengaged users, using purchased lists, or sending spam, can damage both IP and domain reputation.
  • IP Range Impact: The behavior of IPs within the same range can affect each other, potentially leading to range-wide blocks or deliverability issues.
  • Active Monitoring: Email service providers actively monitor IP addresses and use spam complaints as a key factor in determining reputation.
  • Warming Importance: Sudden sending volume spikes from new IPs negatively affect reputation. Gradual IP warming is crucial for new IPs.

Key considerations

  • Monitor Reputation: Regularly monitor your IP and domain reputation to identify and address potential issues proactively using tools like Google Postmaster Tools.
  • List Hygiene: Maintain a clean email list by removing invalid or inactive addresses to improve sender reputation and engagement rates.
  • Sending Practices: Adopt good sending practices, such as sending engaging content to active users, using double opt-in, and honoring unsubscribe requests promptly.
  • Shared IP Awareness: If using shared IPs, be aware of the risks and consider switching to a dedicated IP address for greater control over your reputation.
  • Implement IP Warming: Implement a gradual IP warming strategy when introducing new IPs to establish a positive sending history and avoid triggering spam filters.
  • Comply with Policies: Comply with all applicable email sending policies and regulations, such as GDPR and CAN-SPAM, to avoid penalties and maintain a good reputation.

What email marketers say
12Marketer opinions

IP range behavior significantly impacts email deliverability and domain reputation. Poor sending practices on shared or dedicated IPs can negatively affect the reputation of other IPs within the range and the associated domain. This can lead to blocked IPs, spam folder placement, and overall deliverability issues. Key factors include sending habits, list hygiene, IP warming, and the behavior of neighboring IPs on shared ranges.

Key opinions

  • Shared IP Risk: With shared IPs, the actions of other senders directly impact your reputation. If they send spam or are blacklisted, your deliverability suffers.
  • Domain-IP Link: Domain reputation is closely tied to IP reputation. A domain associated with a bad IP address will experience deliverability problems.
  • Poor Practices Impact: Poor sending practices, like sending to unengaged users or invalid addresses, damage both IP and domain reputation.
  • IP Range Impact: The behavior of IPs within the same range can affect each other, potentially leading to range-wide blocks.
  • Warming Importance: Sudden sending volume spikes from new IPs negatively affect reputation. Gradual IP warming is critical for new IPs.

Key considerations

  • Monitor Reputation: Regularly monitor your IP and domain reputation to identify and address potential issues early.
  • List Hygiene: Maintain a clean email list by removing invalid or inactive addresses to improve sender reputation.
  • Sending Practices: Adopt good sending practices, such as sending engaging content to active users.
  • Neighbor Awareness: If using shared IPs, be aware of the sending practices of other users on the same IP.
  • IP Warming Strategy: Implement a gradual IP warming strategy when introducing new IPs to avoid triggering spam filters.
Marketer view

Email marketer from Mailjet shares that with shared IPs, your sending reputation can be affected by the practices of other senders. If other senders send spam or get blacklisted, your deliverability can suffer.

March 2024 - Mailjet
Marketer view

Marketer from Email Geeks mentions that Microsoft could block the whole range based on behavior from other IPs in the same range.

October 2023 - Email Geeks
Marketer view

Email marketer from SendPulse explains that your IP address and domain reputation are closely linked. If your domain is associated with an IP address that has a poor sending history, this can negatively impact your email deliverability.

February 2025 - SendPulse
Marketer view

Email marketer from Validity explains that bad sending practices, like sending to unengaged users, impacts domain and IP reputation, leading to deliverability issues. It's critical to maintain a clean sending list.

March 2023 - Validity
Marketer view

Email marketer from Moosend mentions that sending emails to invalid or inactive email addresses can hurt your sender reputation. Good list hygiene is critical.

March 2021 - Moosend
Marketer view

Email marketer from StackExchange answers that IP reputation directly affects your deliverability. An IP address with a history of spamming will find it much harder to get emails delivered.

October 2023 - StackExchange
Marketer view

Marketer from Email Geeks responds that if several dedicated IPs are in the same range, the behavior on one IP *could* affect others, but it may not, as there are many variables. Also it's possible you were given an IP that is already on MS' internal blocklist.

December 2024 - Email Geeks
Marketer view

Email marketer from Neil Patel Blog explains that your IP reputation is influenced by your email sending habits. Poor sending practices can damage your IP reputation, leading to deliverability issues for other users on the same IP range.

September 2022 - Neil Patel Blog
Marketer view

Marketer from Email Geeks shares that it's possible that the ESP has a range of IPs impacted if one sender is doing bad enough stuff. Domain reputation is very important and that using the same domain in a different IP range could affect the reputation of that same domain used within a different IP range.

April 2021 - Email Geeks
Marketer view

Email marketer from Litmus shares that your domain reputation matters for email deliverability. A poor domain reputation will result in more emails landing in the spam folder.

June 2024 - Litmus
Marketer view

Email marketer from SparkPost answers that sudden spikes in sending volume from a new IP address can damage your IP reputation. Gradual warming is essential.

February 2024 - SparkPost
Marketer view

Email marketer from Reddit explains that one of the downsides of shared IPs is that you are at the mercy of the other senders. If they send spam, it can affect everyone on the IP, including you.

May 2022 - Reddit

What the experts say
3Expert opinions

These expert insights emphasize the vulnerability of senders sharing IP addresses. The actions of 'noisy neighbors' – senders with poor email practices – can significantly damage the deliverability and reputation of other senders sharing the same IP, particularly affecting smaller volume senders. IP reputation is identified as a crucial factor, directly impacting whether emails are delivered or blocked.

Key opinions

  • Noisy Neighbors: Sharing an IP address exposes senders to the risk of 'noisy neighbors', whose poor sending habits can negatively impact others.
  • Reputation Impact: The actions of other senders on a shared IP directly affect your sending reputation.
  • Deliverability Cruciality: IP reputation is identified as a crucial factor for email deliverability. A negative IP reputation can lead to emails being blocked or sent to the spam folder.

Key considerations

  • Assess Shared IP Risk: Carefully assess the risks associated with shared IP addresses and the potential for neighboring senders to impact your reputation.
  • Monitor Sending Reputation: Actively monitor your sending reputation to detect and address any negative impacts from shared IP usage.
  • Consider Dedicated IP: If feasible, consider switching to a dedicated IP address to gain more control over your sending reputation.
Expert view

Expert from SpamResource explains that a major challenge with shared IPs is the potential for 'noisy neighbors'. The actions of other senders on the same IP can negatively impact your sending reputation.

May 2024 - SpamResource
Expert view

Expert from Word to the Wise explains that the email behavior of your IP neighbors can indeed affect your email deliverability, particularly with smaller volume senders. Being on an IP with senders who are frequently blocked can impact your own reputation.

March 2024 - Word to the Wise
Expert view

Expert from SpamResource answers that your IP reputation is crucial for deliverability. A bad IP reputation can cause your emails to be blocked or sent to the spam folder.

April 2021 - SpamResource

What the documentation says
4Technical articles

Leading email service providers and anti-spam organizations emphasize the critical role of IP reputation in email deliverability. Sending unwanted mail or violating spam policies can damage IP reputation, leading to blocks and deliverability issues. These organizations actively monitor IP addresses and use spam complaints as a key factor in determining reputation.

Key findings

  • IP Reputation Matters: IP reputation is a crucial factor for email deliverability, influencing whether emails reach the inbox.
  • Spam Impact: Sending unwanted mail or violating spam policies negatively impacts IP reputation.
  • Active Monitoring: Email service providers actively monitor IP addresses and their sending behavior.
  • Complaint Significance: The volume of spam complaints received directly affects IP reputation.

Key considerations

  • Adhere to Policies: Strictly adhere to email sending policies to avoid damaging IP reputation.
  • Monitor Complaints: Monitor and address spam complaints promptly to maintain a positive IP reputation.
  • Consent Practices: Implement strong permission and consent practices to minimize sending unwanted mail.
Technical article

Documentation from Google details that IP reputation is a crucial factor for Gmail deliverability. Sending a high volume of unwanted mail from an IP address can negatively impact its reputation and cause deliverability issues.

August 2021 - Google
Technical article

Documentation from Microsoft explains that the sender's IP address reputation is a key factor in determining whether or not an email is delivered to the inbox. They actively monitor the IP addresses used to send email to their services.

November 2022 - Microsoft
Technical article

Documentation from AWS SES shares that they maintain strict policies about sending spam. Violation of these policies will result in suspension of your sending privileges and damage to your IP reputation.

October 2022 - Amazon Web Services
Technical article

Documentation from Spamhaus shares that IP addresses with a history of sending spam are more likely to be blocked by email providers. Your IP reputation is affected by the volume of spam complaints received.

June 2023 - Spamhaus