How to improve email deliverability to Microsoft and avoid spam filters?

Summary

Improving email deliverability to Microsoft and avoiding spam filters involves a holistic approach encompassing technical configuration, sender reputation management, content optimization, and user engagement. Technical aspects include implementing SPF, DKIM, and DMARC for authentication and utilizing Microsoft's SNDS and JMRP for monitoring IP reputation and addressing user complaints. Sender reputation management requires proactively monitoring IP and domain reputation, cleaning email lists by removing inactive subscribers, and gradually warming up new IP addresses. Content should be engaging, personalized, and free of spam triggers, with links and image hosting scrutinized. Encouraging user engagement through segmentation and easy unsubscribe options is crucial. It's also important to be aware that services like Cloudflare, if hosting malicious content, can negatively impact deliverability. Finally, maintain low complaint rates, seek IP delisting if necessary, and prioritize a reputable ESP.

Key findings

  • User Engagement: Targeting engaged users is crucial as Microsoft penalizes sending to unengaged users.
  • Content and Links: User reaction to content, links, and image hosting directly impacts deliverability.
  • Infrastructure Impact: Services like Cloudflare can negatively affect deliverability if they host malicious content.
  • Technical Authentication: SPF, DKIM, and DMARC are essential for authentication but don't guarantee deliverability.
  • List Management: Regular list cleaning by removing inactive addresses improves deliverability.
  • Reputation Monitoring: Monitoring sender reputation, checking blocklists, and using feedback loops are vital.
  • Microsoft Tools: SNDS and JMRP provide valuable data for identifying and addressing deliverability issues with Microsoft.
  • Complaint Reduction: Reducing complaint rates and providing easy unsubscribe options are essential.
  • IP Warm-Up: Gradually warming up new IPs establishes a positive sending reputation.
  • Content Quality: Avoiding spam trigger words and testing emails improves deliverability.

Key considerations

  • Proactive Monitoring: Continuously monitor sender reputation, IPs, and domains to identify and address deliverability issues early.
  • Engagement Focus: Strategically improve user engagement to signal positive sender behavior to Microsoft.
  • Content Optimization: Regularly review and optimize email content and hosting to ensure relevance and avoid spam triggers.
  • Technical Implementation: Implement and maintain proper technical authentication (SPF, DKIM, DMARC).
  • User Experience: Prioritize user experience by providing value and making unsubscribing easy.
  • infrastructure Review: Assess and review infrastructure and associated service deliverability impact.

What email marketers say
10Marketer opinions

Improving email deliverability to Microsoft and avoiding spam filters involves a multifaceted approach. Key strategies include proactive list hygiene by removing inactive subscribers, warming up new IP addresses gradually, and creating engaging and personalized content to reduce spam complaints. Maintaining a good sender reputation, monitoring IP and domain scores, and using a reputable email service provider (ESP) are also essential. Furthermore, simplifying the unsubscribe process and segmenting email lists ensures recipients receive relevant information, which increases engagement and signals positive sender behavior to Microsoft and other ISPs.

Key opinions

  • List Hygiene: Regularly clean your email list by removing inactive subscribers to improve sender reputation.
  • IP Warm-up: Warm up new IP addresses gradually to establish a positive sending reputation.
  • Content Optimization: Avoid spam trigger words and test emails before sending to improve deliverability.
  • Sender Reputation: Maintain a good sender reputation by monitoring IP and domain scores using tools like Sender Score.
  • Complaint Rates: Keep complaint rates low by encouraging whitelisting and simplifying the unsubscribe process.
  • Personalization: Personalize email content to improve engagement and reduce spam complaints.
  • Engagement: Focus on improving email engagement (opens, clicks, replies) to signal positive sender behavior.
  • Segmentation: Segment email lists to ensure recipients receive relevant content, increasing engagement and reducing spam complaints.
  • IP Delisting: Contact the deliverability team to potentially delist an IP address if it has been added to a block list.

Key considerations

  • Proactive Monitoring: Regularly monitor your sender reputation, IP address, and domain to identify and address potential issues before they impact deliverability.
  • ESP Selection: Choose a reputable email service provider (ESP) that follows best practices for deliverability.
  • Recipient Experience: Prioritize the recipient experience by providing valuable content and making it easy to unsubscribe.
  • Authentication Protocols: Implement SPF, DKIM, and DMARC to verify your sending identity.
  • Feedback Loops: Utilize feedback loops and SNDS data to proactively identify if Microsoft is classifying your email as Spam.
Marketer view

Marketer from Email Geeks shares that Pardot's deliverability team reached out to Microsoft on their behalf and got their IP delisted and they sent Microsoft details of their program.

September 2021 - Email Geeks
Marketer view

Email marketer from Mailjet shares that avoiding spam trigger words in email content, using a reputable email service provider (ESP), and testing emails before sending are all important when trying to improve deliverability.

December 2021 - Mailjet
Marketer view

Email marketer from Litmus explains that segmenting your email list based on user behavior and demographics ensures recipients receive relevant content, which increases engagement and reduces spam complaints.

November 2024 - Litmus
Marketer view

Email marketer from Neil Patel explains that cleaning your email list regularly is important. Remove inactive subscribers and those who haven't engaged in a while to improve your sender reputation.

December 2023 - Neil Patel
Marketer view

Email marketer from Gmass explains that focusing on improving email engagement (opens, clicks, replies) sends positive signals to Microsoft and other ISPs, improving deliverability.

December 2024 - Gmass
Marketer view

Email marketer from Quora explains that personalizing email content can improve engagement and reduce the likelihood of recipients marking your messages as spam.

October 2021 - Quora
Marketer view

Email marketer from Reddit shares that maintaining a good sender reputation is key. Monitor your IP and domain reputation using tools like Sender Score and ensure your sending practices are clean.

January 2024 - Reddit
Marketer view

Email marketer from Tech Blog shares that making it easy for users to unsubscribe from your emails prevents them from marking you as spam.

March 2024 - Tech Blog
Marketer view

Email marketer from Sendinblue shares that warming up a new IP address gradually is important when starting to send emails. Start with small volumes and slowly increase it over time to establish a positive sending reputation with Microsoft.

May 2023 - Sendinblue
Marketer view

Email marketer from Email Marketing Forum explains that keeping complaint rates low is critical. Encourage recipients to whitelist your address and make unsubscribing easy.

February 2024 - Email Marketing Forum

What the experts say
6Expert opinions

Improving email deliverability to Microsoft and avoiding spam filters requires a combination of technical configurations, content optimization, and engagement strategies. Expert opinions emphasize the importance of targeting engaged users and maintaining a clean email list by removing inactive addresses. While authentication is crucial for verifying sender identity, content relevance and user interaction play a significant role in deliverability. The use of services like Cloudflare, which may host malicious content, can negatively impact deliverability. Monitoring sender reputation, checking blocklists, and using feedback loops are also key to identifying and resolving deliverability issues proactively.

Key opinions

  • Targeted Engagement: Focus on mailing to engaged users, as Microsoft has become more aggressive on unengaged users.
  • Content and User Reaction: User reactions to your content (including links and image hosting) affect deliverability, even if the content itself hasn't changed.
  • Cloudflare Impact: Using Cloudflare can negatively impact deliverability due to its hosting of malicious content.
  • Authentication Importance: Authentication is crucial for proving identity but does not guarantee deliverability. Content and engagement are also critical.
  • List Hygiene: Regularly remove inactive addresses from your email list to improve deliverability.
  • Reputation Monitoring: Monitor sender reputation and check blocklists to identify and address deliverability issues.

Key considerations

  • Engagement Focus: Prioritize strategies to increase user engagement with your emails.
  • Content Scrutiny: Regularly review and optimize email content, including links and image hosting, to ensure relevance and avoid spam triggers.
  • Reputation Management: Implement processes for actively monitoring and managing your sender reputation.
  • List Maintenance: Establish a routine for identifying and removing inactive subscribers.
  • Cloud Service Evaluation: Carefully evaluate the potential impact of using cloud services like Cloudflare on email deliverability.
Expert view

Expert from Email Geeks shares that using Cloudflare can negatively impact deliverability because it hosts a lot of malicious content, and if one of their sites starts spamming Microsoft, it could hurt your deliverability.

May 2021 - Email Geeks
Expert view

Expert from Word to the Wise explains that proper authentication is crucial, but it's not a magic bullet. It only proves you are who you say you are, and that content and engagement are critical for good deliverability.

February 2023 - Word to the Wise
Expert view

Expert from Email Geeks explains that even if the content hasn't changed, how users are reacting to it might have. Content includes links and image hosting, so those should be checked as well.

September 2023 - Email Geeks
Expert view

Expert from Word to the Wise explains that it's important to remove inactive addresses, stating that regularly scrubbing inactives from your list can improve deliverability to engaged recipients.

June 2021 - Word to the Wise
Expert view

Expert from Spam Resource explains that monitoring your sender reputation is important, and to regularly check blocklists and use feedback loops to identify and address deliverability issues.

October 2022 - Spam Resource
Expert view

Expert from Email Geeks suggests tightening up engaged user targeting because Microsoft has become more aggressive on mailing to unengaged users.

April 2024 - Email Geeks

What the documentation says
4Technical articles

Improving email deliverability to Microsoft and avoiding spam filters, according to official documentation, involves using Microsoft's tools like SNDS (Smart Network Data Services) to monitor sending IP addresses for issues such as complaint rates and spam trap hits. Proper authentication using SPF, DKIM, and DMARC is crucial, along with maintaining low complaint rates and providing easy unsubscribe options. Participating in the Junk Mail Reporting Program (JMRP) allows senders to receive feedback on messages marked as junk, enabling them to identify and fix problems. SparkPost's documentation reinforces the importance of correct implementation of SPF, DKIM, and DMARC for verifying identity and preventing spoofing.

Key findings

  • SNDS Monitoring: Microsoft SNDS provides data on sending IP addresses, including complaint rates and spam trap hits.
  • Authentication: SPF, DKIM, and DMARC are essential for authenticating bulk email.
  • Low Complaint Rates: Maintaining low complaint rates is a key factor in deliverability.
  • Easy Unsubscribe: Providing easy unsubscribe options reduces the likelihood of users marking emails as spam.
  • JMRP Feedback: The Junk Mail Reporting Program (JMRP) allows senders to receive feedback on junk mail reports.

Key considerations

  • Regular Monitoring: Regularly monitor SNDS data for potential deliverability issues.
  • Authentication Setup: Ensure correct implementation of SPF, DKIM, and DMARC authentication protocols.
  • Feedback Loop Integration: Actively participate in the JMRP to receive and address feedback from users.
  • User Experience: Make it easy for recipients to unsubscribe to avoid spam complaints.
Technical article

Documentation from Microsoft SNDS explains that SNDS (Smart Network Data Services) provides data about your sending IP addresses, including complaint rates and spam trap hits, which can help you identify deliverability issues with Microsoft.

November 2022 - Microsoft SNDS
Technical article

Documentation from SparkPost explains that implementing SPF, DKIM, and DMARC authentication protocols correctly helps verify your identity and prevents spoofing, which improves email deliverability.

February 2024 - SparkPost
Technical article

Documentation from Microsoft Postmaster explains that bulk senders should authenticate their email using SPF, DKIM, and DMARC. Also maintain low complaint rates, and provide easy unsubscribe options.

February 2022 - Microsoft Postmaster
Technical article

Documentation from Microsoft JMRP details the Junk Mail Reporting Program (JMRP), which allows senders to receive copies of messages that users mark as junk. This feedback can help identify and fix issues that lead to complaints.

August 2021 - Microsoft JMRP