How can I improve email deliverability to Outlook for outbound prospecting mail if my campaigns are blocked?

Summary

To enhance email deliverability to Outlook for outbound prospecting campaigns, particularly when facing blocks, a comprehensive strategy is essential. Key steps include obtaining explicit opt-in and ensuring content relevance. Utilize list segmentation to target specific groups and personalize emails for better engagement. Maintain list hygiene by promptly removing hard bounces and implementing double opt-in. Proper email authentication via SPF, DKIM, and DMARC is crucial. Monitor sending reputation through Microsoft's SNDS program, and adhere to EOP sending limits and anti-spam policies. Avoid spam trigger words and set recipient expectations. Note that using shared IPs for outbound mail can be problematic, and Return Path certification necessitates a dedicated IP.

Key findings

  • Opt-in and Relevance: Explicit opt-in and relevant content are critical for successful outbound prospecting campaigns and improved deliverability.
  • List Management: Maintaining a clean and engaged email list is vital for a positive sender reputation.
  • Authentication: Properly configured SPF, DKIM, and DMARC records ensure email authentication and trustworthiness.
  • Sending Infrastructure: Avoid using shared IPs for outbound prospecting emails due to potential blocking issues.
  • Compliance: Adhering to sending limits and anti-spam policies set by Microsoft's EOP is essential to avoid blocks.
  • Segmentation & Personalization: Segmenting your email list and personalizing content increases relevance and engagement, improving deliverability.
  • Monitoring & Feedback: Use Microsoft's SNDS program to monitor your sending reputation and promptly address any negative feedback.

Key considerations

  • Shared vs Dedicated IP: Assess the need for a dedicated IP based on campaign volume and sender reputation, especially if pursuing Return Path certification.
  • Data Privacy: Ensure compliance with data privacy regulations (e.g., GDPR, CCPA) when collecting and processing email addresses.
  • Continuous Monitoring: Continuously monitor sending reputation and adapt email practices to maintain high deliverability.
  • Proactive Engagement: Actively manage subscriber expectations and preferences to reduce spam complaints and improve engagement.
  • Alternative Strategies: If outbound prospecting deliverability remains challenging, explore alternative strategies like inbound marketing or partnerships.

What email marketers say
10Marketer opinions

To improve email deliverability to Outlook for blocked outbound prospecting campaigns, several strategies are recommended. Maintaining a clean email list by removing hard bounces is critical, along with implementing double opt-in for new subscribers to ensure genuine interest. Segmentation based on engagement levels helps target more receptive recipients, while personalizing email content increases relevance and trust. Setting recipient expectations regarding email content reduces spam complaints. Technical aspects include proper email authentication using SPF, DKIM, and DMARC, gradually warming up new IP addresses, and avoiding spam trigger words. Additionally, Return Path certification requires dedicated IP and adherence to best practices. List segmentation can be used to improve sender reputation and deliverability.

Key opinions

  • List Hygiene: Removing hard bounces and implementing double opt-in are crucial for maintaining a healthy email list and improving deliverability.
  • Segmentation: Segmenting email lists based on engagement allows for targeted campaigns to recipients who have shown interest.
  • Personalization: Personalized and relevant email content builds trust and increases engagement, positively impacting deliverability.
  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is essential for verifying sender legitimacy and avoiding spam filters.
  • IP Warm-up: Gradually warming up new IP addresses helps establish a positive sending reputation with email providers.
  • Content Optimization: Avoiding spam trigger words in subject lines and content helps prevent emails from being flagged as spam.

Key considerations

  • Dedicated IP: Return Path certification requires a dedicated IP address, which may be necessary for large-scale outbound campaigns.
  • Recipient Expectations: Setting clear expectations about the content and frequency of emails can reduce spam complaints.
  • Best Practices Adherence: Following established email marketing best practices is essential for maintaining a positive sender reputation and high deliverability rates.
  • Legal Compliance: Ensure compliance with data privacy regulations (e.g., GDPR, CCPA) when collecting and using email addresses for outbound prospecting.
Marketer view

Email marketer from Reddit advises segmenting your email list based on engagement levels. Focus your outbound prospecting efforts on subscribers who have shown some interest in your content, as these contacts are less likely to mark your emails as spam.

February 2025 - Reddit
Marketer view

Email marketer from Klenty Blog suggests setting recipient expectations about the emails they'll receive. This helps manage their expectations and reduces the likelihood of them marking the emails as spam

March 2022 - Klenty Blog
Marketer view

Email marketer from GMass Blog suggests warming up a new IP address gradually by starting with low volumes and increasing them over time. This helps establish a positive sending reputation with email providers like Outlook.

January 2025 - GMass Blog
Marketer view

Email marketer from Reddit recommends using double opt-in for all new subscribers. This confirms their interest and helps build a higher quality email list, reducing the risk of spam complaints and improving deliverability.

February 2025 - Reddit
Marketer view

Email marketer from Campaign Monitor Blog explains that personalizing emails and making them relevant to each recipient greatly increases engagement and deliverability as it signals legitimate communication and builds trust with the recipient.

October 2024 - Campaign Monitor Blog
Marketer view

Email marketer from MailerLite Blog explains removing hard bounces from your email list is crucial. Sending to invalid addresses hurts your sender reputation and deliverability. Immediately remove hard bounces to maintain a clean list.

August 2022 - MailerLite Blog
Marketer view

Email marketer from Woodpecker Blog emphasizes the importance of avoiding spam trigger words in your subject lines and email content. Using words or phrases commonly associated with spam can significantly decrease your deliverability rates.

May 2024 - Woodpecker Blog
Marketer view

Email marketer from EmailOctopus Blog explains using list segmentation to send hyper-relevant content to smaller groups of contacts can significantly improve engagement rates, which has a positive knock-on effect on your sender reputation and deliverability.

July 2024 - EmailOctopus Blog
Marketer view

Marketer from Email Geeks mentions that Return Path certification requires a dedicated IP address and strict adherence to best practices, and that Return Path requires strict best practices, if you break those they drop you anyway.

May 2021 - Email Geeks
Marketer view

Email marketer from SparkPost Blog emphasizes the importance of email authentication (SPF, DKIM, DMARC) for improving deliverability. Correctly configuring these records helps email providers verify that your messages are legitimate and reduces the chances of being marked as spam.

December 2024 - SparkPost Blog

What the experts say
4Expert opinions

Improving email deliverability to Outlook for blocked outbound prospecting campaigns requires a multi-faceted approach. Sending from a shared IP for prospecting often leads to blocks that a dedicated IP won't resolve. Instead, focus on obtaining explicit opt-in from recipients and providing highly relevant content. Proper email authentication (SPF, DKIM, DMARC) is crucial for establishing sender legitimacy and avoiding spam filters. Consistent monitoring of sending reputation, using tools like Microsoft's SNDS, and prompt action to address negative feedback are also recommended.

Key opinions

  • Opt-in is Key: Explicit opt-in and relevant content are crucial for outbound prospecting mail to avoid blocks.
  • Authentication Matters: Properly configured SPF, DKIM, and DMARC records are essential for verifying sender identity.
  • Monitor Reputation: Regularly monitor your sending reputation using tools like Microsoft's SNDS to identify and address deliverability issues.
  • IP Address Impact: Sending outbound prospecting mail from shared IP address will cause blocks.

Key considerations

  • Content Relevance: Ensure outbound prospecting emails are highly relevant to recipients' interests to increase engagement and reduce spam complaints.
  • Sender Reputation Management: Actively manage your sender reputation by promptly addressing feedback and resolving any deliverability issues identified through monitoring tools.
  • Authentication Configuration: Verify that SPF, DKIM, and DMARC records are correctly configured and actively maintained for all sending domains.
  • Alternative Strategies: Consider alternative strategies for outbound prospecting if deliverability continues to be a challenge, such as focusing on inbound marketing or utilizing different communication channels.
Expert view

Expert from Spamresource.com suggests to improve cold email deliverability to Outlook, ensure your sending infrastructure is properly configured with SPF, DKIM, and DMARC. Also, consistently monitor your sending reputation using tools like Microsoft's SNDS program, and immediately address any negative feedback.

November 2023 - Spamresource.com
Expert view

Expert from Word to the Wise explains that to avoid blocks for outbound prospecting mail, focus on acquiring explicit opt-in from recipients and ensuring that the content is highly relevant to their interests.

October 2022 - Word to the Wise
Expert view

Expert from Word to the Wise explains that using proper email authentication is crucial to ensure email servers know you are who you say you are. You must use SPF, DKIM and DMARC to authenticate your emails.

July 2021 - Word to the Wise
Expert view

Expert from Email Geeks explains that the issue is likely due to outbound prospecting mail being sent from a shared IP address, which is often blocked. Getting a dedicated IP will not solve the problem, as this type of mail is blocked at the IP level when it's not sent through a provider like Google. Return Path will also not certify outbound prospecting mail because they require opt-in.

June 2024 - Email Geeks

What the documentation says
3Technical articles

Microsoft's documentation highlights several key factors affecting email deliverability to Outlook. The Smart Network Data Services (SNDS) program provides data to monitor sending reputation. Exceeding sending limits defined by Exchange Online Protection (EOP) can result in blocks. EOP's anti-spam policies filter inbound messages, requiring senders to understand and adjust their practices to avoid being flagged.

Key findings

  • SNDS Monitoring: Microsoft's SNDS program offers data for monitoring sending reputation and identifying areas for improvement.
  • Sending Limits: Exceeding sending limits in Exchange Online Protection (EOP) can lead to blocked campaigns.
  • Anti-Spam Policies: Understanding and adhering to Exchange Online Protection's (EOP) anti-spam policies is crucial for avoiding spam filters.

Key considerations

  • Regular SNDS Review: Regularly review data from the Smart Network Data Services (SNDS) program to proactively address sending reputation issues.
  • Limit Compliance: Ensure outbound prospecting campaigns comply with sending limits defined by Exchange Online Protection (EOP).
  • Policy Alignment: Align sending practices with the details described within Exchange Online Protection's (EOP) anti-spam policies to minimize the risk of being flagged as spam.
Technical article

Documentation from Microsoft Learn provides details on how Exchange Online Protection (EOP) uses anti-spam policies to filter inbound messages. It advises understanding these policies and adjusting sending practices to avoid being flagged as spam.

January 2022 - Microsoft Learn
Technical article

Documentation from Microsoft details their Smart Network Data Services (SNDS) program, which provides data about your sending reputation and allows you to monitor your sending practices to improve deliverability to Outlook.com, Hotmail.com, and Live.com.

January 2024 - Microsoft
Technical article

Documentation from Microsoft Learn outlines sending limits in Exchange Online Protection (EOP), noting that exceeding these limits can lead to blocks. It advises understanding and adhering to these limits to avoid deliverability issues.

April 2021 - Microsoft Learn