How long does IP warming take at Microsoft and does mitigation reset reputation?

Summary

Warming an IP at Microsoft typically takes several weeks to months, potentially longer (2-4 months) for a solid reputation, especially for new IPs. Experts and marketers agree that IP warming involves gradually increasing sending volumes. Microsoft's documentation highlights the importance of this gradual process. However, opinions differ regarding mitigation's impact on IP reputation. While one expert states mitigation resets reputation to zero, others, including Microsoft documentation, suggest it aims to restore sending capabilities but doesn't guarantee a complete reset. Post-mitigation, continued monitoring, addressing root causes, maintaining good sending practices, and focusing on content quality and engagement are critical for long-term deliverability success. Microsoft's reputation system is viewed as complex, requiring consistent effort and patience.

Key findings

  • Warmup Duration: Microsoft IP warmup typically takes several weeks to months, potentially longer for new IPs.
  • Mitigation Impact: Mitigation aims to improve deliverability, but complete reputation reset is debated.
  • Gradual Increase: Gradually increasing sending volume is crucial during warmup.
  • Engagement Matters: Engagement metrics and content quality are essential for a good reputation.
  • Continuous Monitoring: Ongoing monitoring post-mitigation is crucial for identifying issues.

Key considerations

  • Plan for Long Warmup: Anticipate a potentially longer IP warming period at Microsoft.
  • Address Root Causes: Investigate and resolve underlying deliverability problems.
  • Maintain Best Practices: Adhere to consistent, ethical sending practices for long-term success.
  • Holistic Approach: Adopt a holistic approach to deliverability, encompassing warmup, content, and engagement.
  • Monitor Reputation: Continuously monitor your sender reputation and adapt your strategies accordingly.

What email marketers say
9Marketer opinions

IP warming at Microsoft typically takes several weeks to months, longer than some other providers, with up to two months needed to establish a good reputation, especially for new IPs. Mitigation efforts improve deliverability but don't guarantee a complete reputation reset. Addressing the underlying issues, consistently practicing good sending habits, monitoring deliverability rates, sending quality content, and focusing on engaged subscribers are crucial for building trust with ISPs and improving overall deliverability.

Key opinions

  • Warming Time: IP warming at Microsoft takes several weeks to months.
  • Mitigation Effect: Mitigation improves deliverability but isn't a complete reputation reset.
  • Content Quality: Quality content and engaged subscribers are key to IP warming success.
  • Monitoring: Continuous deliverability monitoring is essential post-mitigation.
  • Consistency: Consistent good sending habits are critical.

Key considerations

  • Root Cause Analysis: Address underlying deliverability issues to prevent recurrence.
  • Gradual Increase: Increase sending volume gradually during warmup.
  • Engagement Metrics: Focus on engagement metrics to demonstrate value to ISPs.
  • Microsoft Complexity: Microsoft's reputation system is complex, requiring a holistic approach.
  • Patience: Waiting after mitigation may be necessary for Microsoft to recognize improvements.
Marketer view

Email marketer from Iterable states that while mitigation can help recover from deliverability issues, it is crucial to address the root causes to prevent recurrence. It does not guarantee a full 'reset', but rather an opportunity to rebuild reputation.

December 2021 - Iterable
Marketer view

Email marketer from GlockApps mentions that while mitigation helps, it's not a complete reputation reset. Monitoring and addressing deliverability issues post-mitigation is critical.

December 2024 - GlockApps
Marketer view

Email marketer from Email Marketing Forum suggests Microsoft’s reputation system is complex. Even with mitigation, it is important to review sending practices, authentication, and content to ensure future deliverability. Good practices can help maintain and boost reputation.

April 2023 - Email Marketing Forum
Marketer view

Email marketer from Email Vendor Selection says that a slow and steady approach to IP warming is key, typically over several weeks. Focus on quality content and engaged subscribers.

May 2022 - Email Vendor Selection
Marketer view

Email marketer from Reddit explains that even after mitigation, past sending behavior can still influence deliverability. Complete resets are rare, and consistent good sending habits are essential.

January 2022 - Reddit
Marketer view

Email marketer from Mailjet shares that IP warming duration varies, but typically takes several weeks to months. Gradual increases in volume are key to building trust with ISPs.

June 2023 - Mailjet
Marketer view

Email marketer from Email Deliverability Forum shares that it may be a case of waiting after mitigation since it may take time for Microsoft to fully recognize the improved sending reputation. However, it's crucial to keep monitoring deliverability rates and address any issues promptly.

April 2021 - Email Deliverability Forum
Marketer view

Email marketer from SendGrid recommends starting with small sending volumes and gradually increasing over time, focusing on engagement metrics to show ISPs that you're sending valuable email. They advise monitoring deliverability rates during the entire warmup phase.

December 2023 - SendGrid
Marketer view

Email marketer from Reddit shares that warming up an IP at Microsoft can take longer than other providers, sometimes up to 2 months to establish a good reputation, especially with new IPs.

February 2025 - Reddit

What the experts say
3Expert opinions

Microsoft IP warming can take 2-4 months of consistent, good sending to establish a solid reputation. While Microsoft mitigation aims to reset an IP's reputation, other experts suggest that it doesn't always guarantee a complete reset. Consistent sending practices are critical to ensure future deliverability.

Key opinions

  • Warming Time: Microsoft IP warmup: 2-4 months.
  • Mitigation Impact: Conflicting views on mitigation fully resetting reputation.
  • Consistency: Consistent sending practices are crucial.

Key considerations

  • Extended Warmup: Plan for a longer warmup period at Microsoft.
  • Ongoing Monitoring: Monitor deliverability closely even after mitigation.
  • Best Practices: Adhere to consistent and ethical sending practices.
Expert view

Expert from Email Geeks explains that Microsoft IP warmup can take 2-4 months of consistent good sending to establish a solid reputation.

August 2021 - Email Geeks
Expert view

Expert from Email Geeks confirms that Microsoft mitigation resets an IP's reputation to zero.

April 2023 - Email Geeks
Expert view

Expert from Word to the Wise, Laura Atkins, explains that IP warming is a gradual process, and while mitigation aims to improve deliverability, it doesn't always guarantee a complete reset of reputation. Consistent sending practices are critical to ensure future deliverability.

November 2022 - Word to the Wise

What the documentation says
3Technical articles

Microsoft's documentation emphasizes gradual IP warming to establish a positive sender reputation. New IPs require warming to avoid being flagged as spam. Mitigation aims to restore sending capabilities, but doesn't explicitly guarantee a full reputation reset, implying significant improvement is still needed afterward.

Key findings

  • Gradual Warming: IP warming requires gradually increasing sending volume.
  • New IP Reputation: New IPs lack reputation and need warming.
  • Mitigation Aim: Mitigation restores sending but doesn't guarantee full reset.

Key considerations

  • Consistent Increase: Implement a gradual and consistent increase in sending volume during warmup.
  • Reputation Building: Focus on building a positive sending reputation from scratch with new IPs.
  • Post-Mitigation Improvement: Plan for further improvements and monitoring even after mitigation.
Technical article

Documentation from Microsoft SNDS (Smart Network Data Services) clarifies that mitigation processes aim to restore sending capabilities but doesn't explicitly state a 'reset to zero reputation.' However, it implies a significant improvement is needed after mitigation.

January 2024 - Microsoft SNDS
Technical article

Documentation from Microsoft Docs explains that warming up an IP address for sending email involves gradually increasing the volume of email sent from that IP address over a period of time to establish a positive sending reputation with email providers like Outlook.com.

September 2021 - Microsoft Docs
Technical article

Documentation from Microsoft Docs shares that sender reputation is crucial for deliverability. New IPs have no reputation, requiring a gradual warmup to avoid being flagged as spam.

July 2021 - Microsoft Docs