Summary
When Microsoft marks emails as spam from a shared IP address, a multifaceted approach is required to improve deliverability. This includes focusing on sender reputation, content quality, technical setup, and monitoring. Ensuring proper email authentication (SPF, DKIM, DMARC) is critical, and using your own DKIM signature is preferable to a provider-supplied one. Maintaining a clean email list by removing inactive addresses and avoiding spam triggers is essential. Actively monitor your sender reputation via Microsoft's SNDS, subscribe to feedback loops to identify problem recipients, and promptly address negative feedback. Warm up your IP gradually and create engaging content. Furthermore, understand your email sending setup (e.g., Iterable using SES or MTAs on EC2) and ensure servers are fully patched. Remember that on shared IPs, your reputation is influenced by the actions of others.
Key findings
- Email Authentication: Implement SPF, DKIM, and DMARC for proper email authentication and to improve deliverability.
- Clean Email Lists: Maintain a clean email list by regularly removing inactive or invalid addresses.
- Content Optimization: Optimize email content by avoiding spam trigger words and ensuring proper formatting.
- Reputation Monitoring: Monitor sender reputation using Microsoft's SNDS and feedback loops.
- IP Warmup: Gradually warm up IP addresses by increasing email volume over time.
- DKIM Configuration: Ensure DKIM is properly set up with your own domain.
- Server Security: Keep all servers fully patched to prevent them from being compromised and used to send spam.
Key considerations
- Shared IP Limitations: Your sender reputation is influenced by the actions of other users on the shared IP.
- SmartScreen Aggressiveness: Microsoft's SmartScreen filter can be aggressive, and legitimate emails may be marked as spam.
- Dedicated IP as Option: Consider using a dedicated IP for more control over sender reputation if your volume justifies it.
- Feedback Mechanisms: Encourage recipients to mark legitimate emails as 'not junk' to improve future deliverability and make sure you are on feedback loops.
- Hosting Environment: Understand your provider’s sending infrastructure (SES or MTAs on EC2) and its implications for deliverability.
- Proactive Monitoring: Proactively monitor your sending reputation using SNDS and other services.
What email marketers say
12 marketer opinions
When Microsoft marks emails as spam from a shared IP, several strategies can help improve deliverability. Ensuring proper email authentication (SPF, DKIM, DMARC) is crucial. Maintaining a clean email list by removing inactive addresses, avoiding spam trigger words, and properly formatting content are also essential. Monitoring sender reputation via Microsoft's SNDS and other tools is vital for identifying and addressing issues. Actively warming up the IP address, engaging content creation, and encouraging recipients to mark emails as 'not junk' further support improved inbox placement. Finally, understand if your provider is using SES or MTAs on EC2 instances and if this has any affect. Shared IPs require more sender reputation management than dedicated ones.
Key opinions
- Authentication: Implement SPF, DKIM, and DMARC to authenticate emails and prevent spoofing.
- List Hygiene: Regularly clean email lists by removing inactive or invalid addresses.
- Content Optimization: Avoid spam trigger words, ensure proper formatting, and optimize images in email content.
- Reputation Monitoring: Monitor sender reputation using Microsoft's SNDS and other reputation monitoring tools.
- IP Warmup: Gradually warm up IP addresses by increasing email volume over time.
- Engagement: Create engaging content to encourage recipients to interact with emails.
- SNDS Check: Check your IP's reputation using Microsoft's Smart Network Data Services (SNDS) to identify issues.
- Provider Check: Confirm if your provider is using SES or other methods to deliver emails and what this means for deliverability.
Key considerations
- Shared IP Limitations: Understand that sender reputation is influenced by other users on a shared IP.
- SmartScreen Filter: Microsoft's SmartScreen filter can be aggressive, even for legitimate emails.
- Dedicated IP Option: Consider transitioning to a dedicated IP for greater control over sender reputation if volume justifies it.
- Blocklist Monitoring: Regularly check if your IPs and domains are on any blocklists.
- User Feedback: Encourage users to mark legitimate emails as 'not junk' to improve future deliverability.
- EC2 instances vs SES: Determine if provider is using MTAs on EC2 instances for sending or if SES and how this affects IP addresses.
Marketer view
Email marketer from Neil Patel's Blog shares that maintaining a clean email list, engaging content, and consistent sending practices are essential. Monitor your sender reputation and promptly address any issues.
21 Aug 2021 - Neil Patel's Blog
Marketer view
Email marketer from Email Geeks responds that Iterable uses SES, but offers other mail cannons too. She also successfully, but accidentally, got some AmazonSES IPs delisted via Outlook Sender Support.
17 Jan 2025 - Email Geeks
What the experts say
5 expert opinions
When Microsoft marks emails as spam from a shared IP address, it's essential to focus on building and maintaining a positive sender reputation. This involves ensuring correct DKIM setup using your own domain, actively monitoring deliverability, and promptly addressing negative feedback. Utilizing Microsoft's SNDS tool for IP reputation monitoring and subscribing to feedback loops (FBLs) can help identify and remove users marking emails as spam, thereby improving overall deliverability. Your reputation is influenced by other senders on your shared IP.
Key opinions
- DKIM Setup: Ensure correct DKIM setup with your own domain for reputational segmentation.
- Reputation Monitoring: Actively monitor deliverability and promptly address negative feedback.
- Microsoft SNDS: Utilize Microsoft's SNDS tool for IP reputation monitoring.
- Feedback Loops (FBLs): Subscribe to FBLs to identify and remove users marking emails as spam.
Key considerations
- Shared IP Impact: Actions of other senders on the shared IP affect your reputation.
- Proactive Remediation: Proactive monitoring and remediation are key to maintaining a good reputation.
- Engagement Matters: High engagement helps improve inbox placement, but it takes longer with Microsoft.
- Complete DKIM Setup: Many don't fully set up DKIM, so ensure your setup is complete.
Expert view
Expert from Word to the Wise discusses that understanding and utilizing Microsoft's SNDS tool is important for monitoring your IP reputation and identifying potential issues that could lead to emails being marked as spam. Proactive monitoring and remediation are key.
30 Sep 2022 - Word to the Wise
Expert view
Expert from Email Geeks shares that while submitting the form indicating a shared IP might not help much, ensuring DKIM signing with d=your domain can provide some reputational segmentation. High engagement overall, in addition to correct DKIM setup, has helped improve inbox placement, although it takes longer with Microsoft than Gmail.
22 Nov 2021 - Email Geeks
What the documentation says
4 technical articles
When Microsoft marks emails as spam from a shared IP address, key areas to address include sender reputation, content quality, and security. Microsoft's spam filtering is influenced by these factors. Using DMARC to specify how email receivers should handle failed authentication checks can help improve deliverability and combat phishing. Furthermore, with shared IPs, sender reputation is influenced by other users, requiring vigilant monitoring and adherence to email best practices. Keeping all servers patched is essential to prevent compromised servers from sending spam and being blocklisted.
Key findings
- Sender Reputation: Microsoft's spam filtering is heavily influenced by sender reputation.
- Content Quality: Spammy content can lead to emails being marked as spam.
- DMARC Implementation: Implementing DMARC helps combat phishing and improve deliverability.
- Shared IP Influence: With shared IPs, your reputation is affected by other users on the same IP.
- Server Patching: Keeping all servers fully patched is critical for security.
Key considerations
- Holistic Approach: Address sender reputation, content quality, and security simultaneously for best results.
- Dedicated IP: Consider dedicated IPs for greater control over sender reputation.
- Proactive Monitoring: Actively monitor sender reputation and address issues promptly.
- Email Best Practices: Adhere to email best practices to improve deliverability.
Technical article
Documentation from SendGrid Docs explains that with shared IPs, your sending reputation is influenced by other users on the same IP. Monitor your sending reputation, adhere to email best practices, and consider dedicated IPs for greater control.
26 Dec 2022 - SendGrid Docs
Technical article
Documentation from Microsoft Learn explains that several factors influence Microsoft's spam filtering, including sender reputation, content, and user feedback. Poor sender reputation or spammy content can lead to emails being marked as spam.
11 Jul 2024 - Microsoft Learn
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