Summary
During IP warm-up with Microsoft, emails may still land in the junk folder despite good metrics due to several factors beyond IP reputation. Microsoft's filtering system considers content, sender information, recipient engagement, and infrastructure configuration. The lack of established sender reputation, content triggers, poor list hygiene, inconsistent sending volumes, missing or misconfigured email authentication (SPF, DKIM, DMARC), and domain reputation can all contribute. Spam complaints, even in small numbers, significantly impact deliverability. A properly configured reverse DNS record (PTR record) is crucial. Microsoft may implement aggressive throttling on new IPs. Engagement metrics like opens and clicks are vital, and avoiding spam traps is critical. Microsoft's IP reputation colors are unreliable, and their filtering is complex, weighing engagement and sender behavior heavily.
Key findings
- Holistic Filtering: Microsoft uses a holistic filtering approach considering content, sender information, engagement, and infrastructure.
- Sender Reputation: Lack of established sender reputation leads to deliverability issues despite good metrics.
- Content Matters: Content triggers and poor formatting can flag emails as spam.
- List Hygiene Crucial: Poor list hygiene (inactive/invalid addresses) negatively affects deliverability.
- Consistent Volume: Inconsistent sending volumes can confuse ISPs and trigger filters.
- Authentication Essential: Missing/misconfigured SPF, DKIM, DMARC impact deliverability.
- Domain Reputation Counts: Domain reputation overrides IP warm-up efforts if it's poor.
- Complaints Hurt: Even small numbers of spam complaints can severely impact deliverability.
- PTR Record Required: Proper PTR record configuration is a key sender verification step.
- Throttling Possible: Microsoft may aggressively throttle new IPs, limiting sending volume.
- Engagement Is Key: Positive engagement (opens, clicks) is vital for good deliverability.
- Avoid Spam Traps: Hitting spam traps severely damages deliverability.
- Unreliable IP Colors: Microsoft's IP reputation colors are not related to the IP address.
Key considerations
- Optimize All Elements: Optimize content, sender information, infrastructure and engagement.
- Warm Up Properly: Slowly build sending volume to establish a good sending reputation.
- Clean Your List: Maintain a clean email list by removing inactive and invalid addresses.
- Authenticate Your Email: Configure SPF, DKIM, and DMARC to authenticate your emails.
- Monitor Your Reputation: Monitor domain and IP reputation.
- Avoid Spam Traps: Keep up to date with spam traps, remove any in the database.
- Improve Engagement: Improve open rates and click rates with compelling content.
- Configure DNS: Ensure you have a properly configured PTR.
- Handle Complaints: Provide easy unsubscribe and a method to change email preferences.
What email marketers say
10 marketer opinions
During IP warm-up with Microsoft, emails may land in the junk folder despite seemingly good metrics due to various factors beyond IP reputation. These include a lack of established sender reputation, content triggers, poor list hygiene, inconsistent sending volumes, missing or misconfigured email authentication, and the overall reputation of the sending domain. Additionally, Microsoft may implement aggressive throttling, and engagement metrics play a significant role in filtering decisions. Active monitoring of deliverability, avoiding spam traps, and promptly addressing deliverability issues are crucial.
Key opinions
- Sender Reputation: Lack of established sender reputation during IP warm-up can cause emails to land in spam despite good initial metrics.
- Content Triggers: Certain keywords, phrases, or formatting issues in email content can trigger spam filters.
- List Hygiene: Poor list hygiene, including inactive or invalid email addresses, can negatively impact deliverability.
- Sending Volume: Inconsistent sending volumes or rapid increases can confuse ISPs and trigger spam filters.
- Email Authentication: Missing or misconfigured SPF, DKIM, and DMARC records can cause deliverability problems.
- Domain Reputation: The reputation of the sending domain is crucial, regardless of IP warm-up, and a poor domain reputation can lead to spam filtering.
- Engagement Metrics: Engagement metrics such as opens and clicks are factored into placement of emails
- Spam Traps: Hitting spam traps will immediately affect deliverability.
Key considerations
- Establish Sender Reputation: Focus on building a consistent sending history and positive engagement with recipients to establish a solid sender reputation.
- Optimize Email Content: Review and optimize email content to avoid spam triggers and ensure clear, engaging messaging.
- Maintain List Hygiene: Regularly clean email lists to remove inactive or invalid addresses and reduce the risk of spam complaints.
- Ensure Consistent Sending: Maintain consistent sending volumes and avoid rapid increases in email frequency to build trust with ISPs.
- Implement Email Authentication: Properly configure SPF, DKIM, and DMARC records to authenticate emails and improve deliverability.
- Monitor Deliverability: Actively monitor deliverability metrics, including bounce rates, complaint rates, and spam trap hits, to identify and address potential issues.
- Domain Reputation: Audit and improve domain reputation. Review blacklists, check historical data and mitigate as necessary.
- Engagement: Encourage subscribers to engage with emails. This improves sender reputation.
- Monitor for Spam Traps: Keep up to date with any recent spam traps. Remove addresses found from database to avoid deliverability hits.
Marketer view
Email marketer from GlockApps Blog explains that even with proper IP warm-up, sending to a list with poor hygiene can lead to emails landing in spam. A high number of inactive or invalid email addresses on your list can trigger spam filters, regardless of your IP reputation.
11 Jul 2023 - GlockApps Blog
Marketer view
Email marketer from Talos Intelligence highlights that the sending domain's reputation is crucial, regardless of the IP warmup process. Even with a properly warmed-up IP, a domain with a poor reputation can lead to emails being filtered as spam. This includes domain age, historical spam complaints, and association with malicious activities.
19 Aug 2023 - Talos Intelligence
What the experts say
3 expert opinions
Even with good IP metrics, emails may still go to junk due to Microsoft's filtering system. Microsoft filtering relies heavily on content, engagement metrics, and sender behavior. Their IP reputation colors are not fully accurate and are based on content filters. Low engagement signals unwanted content and therefore lands in the junk folder.
Key opinions
- IP Reputation Colors Inaccurate: Microsoft's IP reputation colors are not reliable and are not related to the IP address.
- Complex Filtering System: Microsoft uses a complex filtering system that uses a range of signals beyond IP reputation.
- Engagement Metrics: Engagement metrics are a key part of the filtering system. Low engagement results in landing in the junk folder.
Key considerations
- Focus on Content: Focus on content as that is a key signal that Microsoft uses.
- Improve Engagement: Improve open rates, click rates, and lower deletion rates to show the content is wanted.
- Improve Sender Behavior: Improve overall sender behavior to show the email is valid and wanted.
Expert view
Expert from Word to the Wise explains that Microsoft's filtering is complex and takes into account a wide range of signals beyond just IP reputation, which can cause emails to land in junk even with good sending metrics. They emphasize that content, engagement, and overall sender behavior play a significant role in placement.
5 Feb 2024 - Word to the Wise
Expert view
Expert from Spam Resource shares that Microsoft places significant weight on engagement metrics, especially during IP warm-up. Low open rates, click-through rates, and high deletion rates can signal that the email is unwanted, leading to junk folder placement despite good IP reputation.
3 Jan 2022 - Spam Resource
What the documentation says
4 technical articles
Emails may land in the junk folder during Microsoft IP warm-up, even with good initial metrics, because ISPs consider factors beyond IP reputation. Microsoft considers content, sender information, recipient engagement, and infrastructure configuration. Even small numbers of spam complaints can negatively impact deliverability. A properly configured reverse DNS record (PTR record) is important for sender verification. Finally, engagement metrics such as opens and clicks are crucial for positive deliverability.
Key findings
- Holistic Filtering: Email filtering systems consider factors beyond IP reputation, including content, sender information, recipient engagement, and infrastructure configuration, especially during IP warm-up.
- Spam Complaints Impact: Even small numbers of spam complaints can significantly impact deliverability during IP warm-up.
- Reverse DNS Importance: A properly configured reverse DNS record (PTR record) is crucial for sender verification.
- Engagement Metrics: Engagement metrics such as opens and clicks are crucial for positive deliverability.
Key considerations
- Optimize All Aspects: Optimize content, sender information, recipient engagement, and infrastructure configuration for deliverability.
- Minimize Spam Complaints: Take steps to minimize spam complaints, such as ensuring proper list hygiene and providing easy unsubscribe options.
- Configure Reverse DNS: Ensure a properly configured reverse DNS record (PTR record) for the sending IP address.
- Drive Engagement: Focus on improving engagement metrics by creating compelling content and encouraging interaction.
Technical article
Documentation from RFC Editor highlights the importance of having a proper reverse DNS record (PTR record) configured for your sending IP address. A missing or incorrect PTR record can raise red flags with some ISPs, especially during IP warm-up, and increase the likelihood of emails being filtered as spam.
12 Feb 2023 - RFC-Editor
Technical article
Documentation from Microsoft Support explains that their email filtering systems consider various factors beyond IP reputation, especially during new IP warm-up. These factors include content, sender information, recipient engagement, and infrastructure configuration. Even with good initial metrics, the filtering logic might initially place emails in junk folders until a sufficient reputation is built across these areas.
2 Oct 2024 - Microsoft Support
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