How to troubleshoot Office 365 SCL varying issues when deliverability is fine elsewhere?

9 Marketer opinions 5 Expert opinions 4 Technical articles 3 Resources

Summary

Troubleshooting inconsistent SCL scores in Office 365 when general email deliverability is satisfactory involves a multi-faceted approach. Start by verifying email authentication using SPF, DKIM, and DMARC, considering Microsoft's stringent standards. Monitor sender reputation metrics like bounce and complaint rates. Utilize Microsoft's Smart Network Data Services (SNDS) to specifically track IP reputation within their ecosystem. If blocked, use the delist portal providing all required information. Examine message headers using the Microsoft Message Analyzer to understand triggered anti-spam rules. Administrators can fine-tune SCL thresholds in Exchange Online to reduce false positives and use the Mail flow dashboard for issue tracking. Employ best practices for subscriber management including segmentation and feedback loops. Instruct recipients to check spam folders and contact their IT department if messages are not received. Ensure that the 'From' name and content align with initial subscription promises. Be aware that direct support from Microsoft outside the ticketing system is limited.

Key findings

Authentication is Key: Valid SPF, DKIM, and DMARC records are paramount due to Microsoft's strict authentication requirements.
SNDS is Essential: Microsoft's SNDS provides crucial insights into IP reputation specific to their filtering systems.
SCL Thresholds Matter: Administrators can adjust SCL thresholds in Exchange Online to fine-tune spam filtering.
Recipient Action Helps: Instructing recipients to check spam and whitelist senders is a viable workaround.
Header Analysis Reveals Insights: Analyzing message headers with Microsoft tools can uncover specific anti-spam triggers.
Sender Reputation Affects SCL: Bounce rates, complaint rates, and engagement metrics influence SCL scores within Microsoft 365.

Key considerations

Regular Authentication Checks: Periodically review SPF, DKIM, and DMARC configurations to ensure accuracy and validity.
Proactive SNDS Monitoring: Consistently monitor SNDS data for early detection of reputation or deliverability issues.
Segment and Clean Lists: Implement list segmentation and regularly remove inactive subscribers to improve engagement and reduce spam flags.
Provide Clear Communication: Inform recipients about possible delivery issues and guide them on how to ensure they receive messages.
Use Ticketing System: When facing persistent issues, engage with Microsoft through their ticketing system, as direct support outside is limited.

What email marketers say
9Marketer opinions

Troubleshooting Office 365 SCL issues with good deliverability elsewhere involves several key steps. First, ensure proper email authentication (SPF, DKIM, DMARC) and maintain a good sender reputation by monitoring bounce rates, complaint rates, and engagement metrics. Use Microsoft's SNDS program to specifically track your IP reputation with Microsoft. Review message headers for anti-spam stamps and use the Microsoft Message Analyzer for detailed diagnostics. Manage your subscriber list, segment based on engagement, and use feedback loops to monitor complaints. Ensure consistency between the 'From' name, content, and subscription offers. Finally, check against major blocklists and utilize the delist portal if necessary.

Key opinions

SCL Factors: SCL is influenced by sender reputation, content, and recipient interactions, leading to variations even with generally good deliverability.
Authentication: Proper SPF, DKIM, and DMARC records are essential for authenticating emails and proving legitimacy to Microsoft 365.
Reputation Monitoring: Maintaining a good sender reputation through monitoring bounce rates, complaint rates, and engagement metrics is crucial.
Microsoft SNDS: Using Microsoft's SNDS program provides insight into IP reputation specifically within Microsoft's filtering systems.
Header Analysis: Reviewing message headers and using the Microsoft Message Analyzer can reveal specific anti-spam rules being triggered.
Blocklist Checks: Ensure your sending IPs and domains are not listed on any major blocklists.

Key considerations

Subscriber Management: Actively manage subscriber lists, segment based on engagement, and remove inactive recipients to improve engagement metrics.
Content Consistency: Ensure consistency between the 'From' name, content, and what was offered during subscription to avoid triggering spam filters.
Feedback Loops: Utilize feedback loops to monitor complaints from Microsoft users and address issues promptly.
Delisting Portal: Use the delist portal if your IP address has been blocked by Microsoft, providing necessary information to expedite the process.

Marketer view

Email marketer from MXToolbox explains that implementing SPF, DKIM, and DMARC are essential to authenticate your emails, proving to Microsoft 365 that you are a legitimate sender. Also ensure your sending IPs/domains aren't on any major blocklists.

July 2023 - MXToolbox

Marketer view

Email marketer from Reddit shares the advice to check the sender's IP address against blacklists, ensure proper SPF, DKIM, and DMARC records are in place, and advise recipients to add the sender to their safe sender list. Further advises to use the delist portal.

November 2023 - Reddit

Marketer view

Email marketer from Microsoft Community explains that SCL (Spam Confidence Level) is affected by various factors, including sender reputation, content, and recipient interactions. Even with good deliverability elsewhere, Microsoft 365 might still flag emails based on its own criteria.

March 2023 - Microsoft Community

Marketer view

Email marketer from Practical 365 responds that Exchange Online Protection (EOP) uses a combination of technologies to prevent spam from reaching inboxes. SCL values are assigned based on these checks. To resolve deliverability issues, ensure proper authentication (SPF, DKIM, DMARC), monitor reputation, and use the Microsoft SNDS program.

May 2024 - Practical 365

Marketer view

Email marketer from EmailAcademy recommends ensuring the 'From' name is consistent with the brand and that the content matches what was offered when the user subscribed.

October 2023 - EmailAcademy

Marketer view

Email marketer from Sendgrid recommends using feedback loops to monitor complaints from Microsoft users. Actively manage your subscriber list to remove inactive or disengaged recipients.

October 2021 - Sendgrid

Marketer view

Email marketer from MailerQ shares that segmenting your email lists based on engagement levels is essential. Send targeted campaigns to active subscribers to improve engagement metrics and reduce the likelihood of being flagged as spam.

November 2022 - MailerQ

Marketer view

Email marketer from Stack Overflow shares that you should review the message headers for specific anti-spam stamps or rules being triggered. Use the Microsoft Message Analyzer to diagnose the detailed reasons for the SCL scoring.

October 2021 - Stack Overflow

Marketer view

Email marketer from Mailjet shares that maintaining a good sender reputation is key. Monitor bounce rates, complaint rates, and engagement metrics. High bounce rates and complaints can negatively impact your SCL score in Microsoft 365.

June 2023 - Mailjet

What the experts say
5Expert opinions

Troubleshooting Office 365 SCL variations despite good overall deliverability involves understanding Microsoft's specific policies and technical requirements. Microsoft doesn't provide individual support outside its ticketing system, so direct contact is unlikely to resolve issues. Key actions include advising recipients to check spam folders and mark emails as 'Not Spam,' particularly for transactional messages, and instructing users to contact their IT department if emails are not received at all. Utilizing Microsoft's Smart Network Data Services (SNDS) is crucial for monitoring IP reputation with Microsoft. Finally, ensure correct SPF, DKIM, and DMARC records, as Microsoft has stricter authentication standards than other providers.

Key opinions

Limited Direct Support: Microsoft's policy restricts individual support to its ticketing system, limiting external assistance.
Recipient Action: Encouraging recipients to check spam folders and mark emails as 'Not Spam' is a practical workaround.
IT Department Contact: If emails are not received at all, the recipient's IT department should be contacted.
SNDS Importance: Microsoft's Smart Network Data Services (SNDS) is essential for monitoring IP reputation specifically within Microsoft's filtering systems.
Authentication: Correct SPF, DKIM, and DMARC records are vital due to Microsoft's stricter authentication standards.

Key considerations

Ticket Submission: Focus efforts on utilizing Microsoft's official ticketing system for issue reporting.
User Education: Educate recipients on checking spam folders and marking emails as 'Not Spam' to improve deliverability.
SNDS Monitoring: Regularly monitor SNDS for insights into complaint rates and potential blocking issues.
Authentication Verification: Periodically verify SPF, DKIM, and DMARC records to ensure they are correctly configured and up-to-date.

Expert view

Expert from Email Geeks advises that if recipients do not receive the message at all, they should contact their IT department.

April 2023 - Email Geeks

Expert view

Expert from Email Geeks explains Microsoft's policy of not providing individual help outside of the ticketing system due to legal constraints. Reaching out to contacts on the M3AWG website is also unlikely to yield results.

April 2021 - Email Geeks

Expert view

Expert from Word to the Wise recommends checking your authentication. Check your SPF, DKIM and DMARC records are correct. Microsoft often has stricter authentication requirements, so misconfigured records can lead to deliverability issues even if other providers accept the mail.

October 2023 - Word to the Wise

Expert view

Expert from Email Geeks suggests instructing recipients to check their spam folders and mark transactional emails as 'Not Spam,' especially if they are Microsoft O365 users. Also suggests to include the notification on the website where the user triggers the transaction.

April 2024 - Email Geeks

Expert view

Expert from Word to the Wise explains that you need to use Microsoft's Smart Network Data Services (SNDS) program to monitor your IP reputation with Microsoft. This provides insight into complaint rates and potential blocking issues specific to Microsoft's filtering systems, which can vary even if overall deliverability is good. By monitoring it you can diagnose deliverability issues specific to Microsoft domains.

January 2022 - Word to the Wise

What the documentation says
4Technical articles

Troubleshooting varying SCL issues in Office 365, despite good deliverability elsewhere, involves utilizing administrative tools and understanding SCL values. Administrators can adjust spam filter policies in Exchange Online to fine-tune filtering aggressiveness and reduce false positives. Understanding SCL values, ranging from -1 to 9, helps in identifying why messages are being flagged. The Mail flow dashboard in the Exchange admin center (EAC) aids in tracking and resolving email delivery issues. If an IP address is blocked, the delist portal can be used to request removal, requiring thorough completion of instructions and information.

Key findings

SCL Threshold Adjustment: Administrators can modify spam filter policies in Exchange Online to adjust SCL thresholds.
SCL Value Interpretation: Understanding SCL values (ranging from -1 to 9) is crucial for identifying false positives.
Mail Flow Dashboard: The Mail flow dashboard in the EAC helps track and resolve email delivery issues.
Delist Portal Usage: The delist portal is used to request removal of blocked IP addresses.

Key considerations

Fine-tuning Spam Filters: Carefully adjust spam filter policies to balance security and prevent false positives.
Proactive Monitoring: Regularly monitor the Mail flow dashboard for any delivery issues.
Complete Delisting: When using the delist portal, provide all required information accurately to expedite the process.

Technical article

Documentation from Microsoft details the process of using the Mail flow dashboard in the Exchange admin center (EAC) to track and resolve email delivery issues. This tool can help identify if messages are being blocked or delayed by Exchange Online Protection (EOP).

November 2021 - Microsoft Learn

Technical article

Documentation from Microsoft outlines that SCL values range from -1 to 9, with higher values indicating a greater probability that a message is spam. Understanding these values can help troubleshoot why certain messages are being flagged, even if deliverability to other providers is good.

October 2022 - Microsoft Learn

Technical article

Documentation from Microsoft explains how to adjust the SCL thresholds. Admins can modify the spam filter policies in Exchange Online to adjust how aggressively messages are filtered based on SCL ratings. This can help fine-tune spam filtering to reduce false positives.

March 2023 - Microsoft Learn

Technical article

Documentation from Microsoft explains using the delist portal. If your IP address has been blocked by Microsoft, use the delist portal to request removal. Follow the instructions and provide all necessary information to expedite the process.

March 2022 - Microsoft Support