Send & Receive Issues

How to Fix a Microsoft IP Address Blocked by SpamCop

Maira Mehtab Sep 21, 2026 868 views

Question details

An email sent from a Microsoft-owned IP address has been listed on the SpamCop blocklist, causing email delivery failures.

Product: Microsoft 365
Device & OS: not provided
Scenario: Users are experiencing email send and receive issues because their organization's shared Microsoft IP is blocked by the SpamCop service.
Observed behavior: Outgoing emails are rejected or marked as spam by recipients, and the organization needs to determine how to get the IP address removed from the blocklist.

Before you start

Ensure you have Microsoft 365 administrator privileges, as resolving IP blocklist issues requires access to Exchange admin center message traces and the ability to open support requests.

Solution 1Recommended

Investigate Sending Logs and Secure Your Environment

Identify the root cause of the block by checking for compromised accounts or misconfigurations before requesting delisting.

Microsoft cannot directly remove an IP address from SpamCop's blocklist. SpamCop automatically removes IPs once the spamming behavior stops, so finding the source of the issue within your organization is critical.

Check message traces

Review sending logs

Analyze your sending logs to locate potentially compromised user accounts that might be sending bulk spam.

Secure compromised accounts

If a suspicious account is found, immediately reset its password, revoke active sessions, and review inbox rules for unauthorized forwarding.

Verify domain authentication

Ensure your domain's SPF, DKIM, and DMARC records are correctly configured to prevent spoofing.

Automatic Delisting: SpamCop listings are typically temporary and may be removed automatically after the spam-sending behavior from the affected IP address ceases.

Solution 2

Update Safe-Sender Lists and Open a Support Request

Mitigate immediate email flow issues and escalate to Microsoft 365 support for further investigation.

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Frequently Asked Questions

Why did SpamCop block a Microsoft IP address?

SpamCop blocks IP addresses when it receives reports of spam originating from that IP. In a shared hosting environment like Microsoft 365, a compromised account from another organization sharing the same IP can temporarily affect the IP's reputation for everyone.

Can I manually remove my Microsoft IP from SpamCop?

No, neither you nor Microsoft can directly force SpamCop to remove an IP address. SpamCop operates an automated system that evaluates traffic and delists IPs once the reported spamming activity stops.

How long does a SpamCop blocklist last?

SpamCop listings are dynamic and generally temporary. If no further spam is detected from the IP address, it is usually automatically delisted within 24 to 48 hours.

What should I do if my emails are immediately rejected due to a SpamCop block?

First, review your outbound message traces to ensure no compromised accounts in your tenant are sending spam. Then, ask your recipient to temporarily add your domain to their safe-sender list, or contact Microsoft 365 support to investigate the shared IP issue.

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