How can I improve email deliverability with Microsoft and avoid spam filters?

Summary

Improving email deliverability with Microsoft and avoiding spam filters requires a comprehensive strategy that encompasses technical setup, ongoing maintenance, and proactive engagement. Key elements include establishing and maintaining a strong sender reputation through consistent sending practices and valuable content, implementing proper email authentication (SPF, DKIM, DMARC) to verify sender identity, practicing diligent list hygiene by removing inactive subscribers and managing bounce rates, actively encouraging recipient engagement, gradually warming up IP addresses, and monitoring key metrics using tools like Microsoft's SNDS. Additionally, persistent communication with Microsoft support and adherence to their guidelines and policies are vital for addressing deliverability issues.

Key findings

  • Sender Reputation is Paramount: Microsoft, like other ISPs, heavily relies on sender reputation to determine email acceptance. A strong reputation is built through consistent sending practices, valuable content, proper authentication, and minimal spam complaints.
  • Authentication is Crucial: Proper email authentication (SPF, DKIM, DMARC) is not optional; it's a fundamental requirement to prove sender legitimacy and prevent spoofing.
  • List Hygiene is Essential: Maintaining a clean email list by removing inactive subscribers, managing bounce rates, and implementing double opt-in significantly improves deliverability.
  • Engagement Matters: Encouraging recipients to engage with emails through clicks, replies, and marking as 'not spam' positively impacts sender reputation and deliverability.
  • Microsoft Support is a Resource: Don't hesitate to persistently engage with Microsoft support for assistance, especially during IP warmups or when facing persistent deliverability challenges.
  • IP Warmup is Critical: When starting with a new IP address, a gradual warmup process is crucial to establish trust with Microsoft and avoid being flagged as spam.
  • Monitoring is Key: Continuously monitor key metrics like open rates, click-through rates, bounce rates, spam complaints, and feedback loop (FBL) complaints to identify and address deliverability issues promptly using Microsoft SNDS and other tools.

Key considerations

  • Prioritize Valuable Content: Focus on delivering valuable and relevant content that resonates with your subscribers to improve engagement and reduce spam complaints.
  • Regularly Review and Update Authentication Records: Ensure that SPF, DKIM, and DMARC records are correctly configured and regularly reviewed to maintain proper authentication.
  • Implement a Double Opt-in Process: Use a double opt-in process to verify subscribers' email addresses and ensure that only genuinely interested users are added to your list.
  • Segment Your Audience: Segment your audience to send more targeted and relevant emails, which can improve engagement and reduce unsubscribe rates.
  • Use Online Validators: Utilize online validators to confirm your SPF, DKIM, DMARC are setup correctly.
  • Avoid Spam Trigger Words: Take care to avoid using spam trigger words in subject lines and email body content.
  • Adhere to Microsoft's Policies: Thoroughly review and adhere to Microsoft's sender guidelines and best practices to ensure compliance and optimize deliverability.

What email marketers say
10Marketer opinions

To improve email deliverability with Microsoft and avoid spam filters, a multi-faceted approach is required. Key strategies include building and maintaining a good sender reputation by sending valuable content and engaging recipients, focusing on list hygiene by removing inactive users, and implementing proper email authentication (SPF, DKIM, DMARC). Warming up IP addresses gradually and monitoring engagement metrics such as open rates and spam complaints are also crucial. When issues arise, being persistent in communicating with Microsoft support, opening tickets for pre-emptive accommodation, and carefully reviewing deliverability guides and error messages can help in diagnosing and resolving filtering problems.

Key opinions

  • Sender Reputation: Building and maintaining a positive sender reputation with Microsoft is crucial for ensuring email deliverability. Consistently sending valuable and engaging content contributes significantly to a positive reputation.
  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is essential. Ensure these protocols are correctly configured and validated to verify the authenticity of your emails and prevent spoofing.
  • List Hygiene: Maintaining a clean email list by removing inactive or disengaged subscribers reduces bounce rates and spam complaints, ultimately improving deliverability.
  • Engagement Metrics: Monitoring engagement metrics like open rates, click-through rates, and spam complaints provides valuable insights into subscriber behavior and the effectiveness of your email campaigns.
  • Microsoft Support: Being persistent in contacting Microsoft support and opening tickets, even for pre-emptive accommodation, can help resolve deliverability issues.
  • IP Warmup: Gradually warming up IP addresses is important, particularly when using a new sending IP or domain

Key considerations

  • Preemptive Action: Consider proactively contacting Microsoft support when starting a new email program or warming up an IP to request preemptive adjustments to their filtering.
  • Ticket Persistence: Be prepared to persistently follow up on support tickets, even when receiving canned responses, to ensure your deliverability issues are addressed.
  • SPF Record Alignment: Double-check and update your SPF records to ensure they are properly aligned with your sending infrastructure, as this can have an immediate positive impact on open rates.
  • Engagement is Key: Pay attention to engagement metrics, as low engagement signals potential issues and the need to improve content and targeting.
  • Review Microsoft Guidelines: Familiarize yourself with Microsoft's deliverability guidelines and troubleshoot based on error messages. Look into Microsoft SNDS (Smart Network Data Services).
Marketer view

Marketer from Email Geeks suggests opening a ticket with Microsoft for "preemptive accommodation" when starting a warmup, requesting adjustments to their filtering.

July 2023 - Email Geeks
Marketer view

Email marketer from Neil Patel explains that improving sender reputation is key by consistently sending valuable content that recipients engage with. They advise cleaning email lists regularly to remove inactive subscribers and using double opt-in to ensure only genuinely interested users are added.

November 2022 - Neil Patel
Marketer view

Email marketer from Sendinblue shares that to land emails in the inbox, you need to focus on building a clean email list, authenticating your emails, avoiding spam trigger words, and engaging your subscribers. They recommend segmenting your audience to send more targeted emails and using A/B testing to optimize your campaigns.

July 2023 - Sendinblue
Marketer view

Marketer from Email Geeks shares a mantra for dealing with Microsoft deliverability issues and suggests persistent ticket filing for good senders.

May 2024 - Email Geeks
Marketer view

Email marketer from EmailGeek Forum explains the importance of monitoring engagement metrics like open rates, click-through rates, and conversion rates to gauge subscriber interest and identify areas for improvement. Low engagement indicates that your content might not be resonating with your audience, which can negatively impact deliverability.

March 2024 - EmailGeek Forum
Marketer view

Marketer from Email Geeks shares that updating the SPF record to be properly aligned after reviewing Microsoft's deliverability guide led to immediate improvement in open rates.

December 2023 - Email Geeks
Marketer view

Email marketer from Reddit shares that to deal with Microsoft filtering, focus on warming up your IP address gradually, monitoring your sender reputation in Microsoft's SNDS (Smart Network Data Services), and addressing any feedback loop (FBL) complaints promptly. They suggest reaching out to Microsoft's support team if deliverability issues persist.

May 2024 - Reddit
Marketer view

Email marketer from Stack Overflow explains that it's important to ensure SPF, DKIM and DMARC are correctly configured. He suggests checking the syntax and using online validators to ensure they are setup correctly, also checking your domain isn't listed on any blacklists.

May 2024 - Stack Overflow
Marketer view

Marketer from Email Geeks suggests being persistent on tickets with Microsoft, even if they provide canned responses, to eventually get adjustments made.

March 2022 - Email Geeks
Marketer view

Email marketer from Mailjet shares that several factors influence email deliverability, including authentication (SPF, DKIM, DMARC), sender reputation, content quality, and engagement metrics. They emphasize the importance of monitoring bounce rates, spam complaints, and unsubscribe rates to identify and address issues promptly.

November 2023 - Mailjet

What the experts say
4Expert opinions

Improving email deliverability with Microsoft hinges on several key areas: maintaining a strong sender reputation through consistent sending practices, proper authentication, and minimal spam complaints; ensuring a clean email list by removing invalid addresses and unengaged subscribers; prioritizing engagement by encouraging recipients to interact with your emails; and implementing a gradual warmup process when starting with a new IP address or domain. These actions contribute to a positive reputation with Microsoft and prevent emails from being flagged as spam.

Key opinions

  • Sender Reputation: Microsoft uses sender reputation to determine email acceptance. A good reputation requires consistent sending, proper authentication, and few spam complaints.
  • List Hygiene: Maintaining a clean email list by removing invalid and unengaged addresses improves deliverability and sender reputation.
  • Engagement: Encouraging recipients to engage with your emails positively impacts your reputation with Microsoft.
  • Warmup Process: Gradually increasing sending volume from new IPs or domains is crucial for establishing a positive sender reputation.

Key considerations

  • Consistency: Maintain consistent sending practices and content to build a reliable sender reputation.
  • Authentication: Ensure proper email authentication (SPF, DKIM, DMARC) is in place to verify your identity.
  • Subscriber Activity: Regularly monitor and remove inactive subscribers to improve list quality and engagement rates.
  • Gradual Ramp-Up: Implement a gradual warmup strategy to build trust with Microsoft when introducing new infrastructure.
Expert view

Expert from Word to the Wise explains that maintaining a clean email list is critical for email deliverability. This includes removing invalid email addresses, unsubscribed users, and those who haven't engaged with your emails in a while. Regularly cleaning your list helps reduce bounce rates and spam complaints, which can negatively impact your sender reputation with Microsoft.

May 2023 - Word to the Wise
Expert view

Expert from Word to the Wise explains that Engagement is a crucial factor. Encouraging recipients to engage with your emails by clicking links, replying, or marking them as 'not spam' helps build a positive reputation with Microsoft. Monitor your engagement metrics and adjust your content and sending frequency accordingly to maximize recipient interaction.

November 2024 - Word to the Wise
Expert view

Expert from Spam Resource explains that a key factor in deliverability is sender reputation. Microsoft, like other ISPs, uses sender reputation to determine whether to accept, reject, or filter incoming email. Building a good sender reputation takes time and effort, and requires consistent sending practices, proper authentication, and minimal spam complaints.

September 2021 - Spam Resource
Expert view

Expert from Spam Resource explains that when starting to send emails from a new IP address or domain, it's important to gradually increase your sending volume over time, known as a warmup process. This helps establish a positive sender reputation with Microsoft and prevents your emails from being flagged as spam.

February 2024 - Spam Resource

What the documentation says
5Technical articles

Improving email deliverability with Microsoft and avoiding spam filters requires adherence to established best practices and technical standards. Key actions include following Outlook.com's sender guidelines, implementing SPF to authorize sending mail servers, employing DMARC to handle authentication failures and prevent spoofing, and adhering to general bulk sender guidelines like those provided by Google, which emphasize authentication, low spam rates, and easy unsubscribe options. Managing bounce rates by maintaining clean email lists is also crucial for preserving sender reputation.

Key findings

  • Microsoft Policies: Outlook.com has specific policies and practices for senders. Adhering to these guidelines is essential for inbox placement.
  • SPF: Sender Policy Framework (SPF) authorizes mail servers to send email on behalf of your domain. This prevents spoofing and improves deliverability.
  • DMARC: DMARC builds on SPF and DKIM to provide a policy for handling emails that fail authentication. This protects against spoofing and phishing.
  • Bulk Sender Guidelines: General bulk sender guidelines (e.g., Google's) emphasize authentication, low spam rates, and easy unsubscribe options for better deliverability.
  • Bounce Rate Management: Managing bounce rates is critical for deliverability. High bounce rates damage sender reputation.

Key considerations

  • Compliance: Ensure full compliance with Outlook.com's sender policies and guidelines to optimize inbox placement.
  • Authentication Implementation: Properly configure and maintain SPF records to authorize legitimate sending sources.
  • DMARC Policy: Implement a DMARC policy to instruct email receivers on how to handle unauthenticated emails from your domain.
  • List Hygiene: Regularly clean your email lists to remove invalid and inactive addresses, minimizing bounce rates.
  • Unsubscribe Process: Offer a clear and easy unsubscribe process to allow recipients to opt-out, minimizing spam complaints.
Technical article

Documentation from Microsoft outlines Outlook.com's policies and practices for senders, including authentication requirements, spam filtering criteria, and best practices for maintaining a positive sender reputation. They detail the importance of adhering to these guidelines to ensure emails are delivered to the inbox and not marked as spam.

March 2024 - Microsoft
Technical article

Documentation from RFC explains that Sender Policy Framework (SPF) allows you to specify the mail servers that are authorized to send email on behalf of your domain. Creating an SPF record can prevent spammers from forging your email address and improve email deliverability. It's set up as a DNS TXT record.

June 2023 - RFC
Technical article

Documentation from Google shares that its bulk sender guidelines include authenticating your email using SPF, DKIM, and DMARC; maintaining low spam rates; and providing easy unsubscribe options. Adhering to these guidelines can help improve your sender reputation and increase the likelihood of your emails reaching the inbox. Although focused on Gmail, many principles are universal.

January 2024 - Google
Technical article

Documentation from DMARC.org details that DMARC (Domain-based Message Authentication, Reporting & Conformance) builds upon SPF and DKIM to provide a policy for handling emails that fail authentication checks. Implementing DMARC helps protect your domain from email spoofing and phishing attacks, and improves email deliverability.

October 2024 - DMARC.org
Technical article

Documentation from SparkPost details that managing your bounce rate is vital for email deliverability. High bounce rates can damage your sender reputation and lead to filtering issues. They advise regularly cleaning your email lists to remove invalid or inactive addresses and implementing mechanisms to prevent invalid addresses from being added to your list.

January 2024 - SparkPost