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How to Fix Exchange Online Email Blocked by SpamCop IP Listings
Question details
Microsoft 365 and Exchange Online messages are being rejected because the shared sending IP addresses appear on the SpamCop blocklist.
- Product
- Exchange Online
- Device & OS
- not provided
- Scenario
- Sending outbound emails to external recipients using Microsoft 365 shared infrastructure.
- Observed behavior
- Emails fail to deliver and return Non-Delivery Reports (NDRs) indicating the sending IP address is blocked by SpamCop.
Gather your Non-Delivery Report (NDR) bounce messages and note the exact affected IP addresses, timestamps, and recipient error codes before contacting support.
Open a Microsoft 365 Service Request with NDR Details
Escalate the issue to Microsoft Support, as individual tenants cannot delist shared Exchange Online IPs from SpamCop.
Because the affected IP addresses (such as 40.107.107.92) belong to Microsoft's shared Exchange Online infrastructure, individual domain administrators cannot request delisting from SpamCop directly.
Microsoft handles the IP reputation for their shared pools. You must provide them with the necessary bounce evidence so their backend team can investigate the sending range, rotate IPs, and resolve the blocklist listing.
Open the bounce email (Non-Delivery Report) and copy the rejected-message details, including the affected IP addresses, timestamps, and specific recipient errors.
Navigate to the Microsoft 365 admin center (admin.microsoft.com) and log in with your global administrator or Exchange administrator credentials.
Click on the Support menu in the left navigation pane, select Help & Support, and open a new service request to report the Exchange Online sending IP reputation issue.
If the delivery failure is intermittent, continue documenting and attaching each new occurrence to your open ticket to help Microsoft isolate the problematic sending range.
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Frequently Asked Questions
Why is my Microsoft 365 IP on the SpamCop blocklist?
Microsoft 365 utilizes a shared IP infrastructure, meaning multiple tenants send emails from the same IP range. If one tenant sends bulk spam or compromised emails, the shared IP may temporarily get flagged by SpamCop, affecting other legitimate businesses using the same IP.
Can I manually delist the Exchange Online IP from SpamCop?
No, individual Microsoft 365 tenants cannot delist shared Exchange Online IPs from SpamCop. The IP block belongs to Microsoft, and only Microsoft can negotiate removal or rotate the sending IP pool to restore reputation.
How long does it take for Microsoft to resolve the SpamCop blocklist issue?
Resolution times vary depending on the severity of the listing and Microsoft's internal investigation. Providing detailed Non-Delivery Reports (NDRs) in your Microsoft 365 service request will help expedite the investigation process.
