Microsoft Blacklist Check: Fix Outlook and Hotmail Delivery

Microsoft Blacklist Check

A Microsoft blacklist check tells you whether your IP or domain is on Microsoft's own block list, which specifically affects delivery to Outlook, Hotmail, and Live addresses.

Why Microsoft is its own case

Microsoft runs its own reputation system separate from public DNSBLs. You can be clean on Spamhaus and still blocked at Outlook, so Outlook and Hotmail delivery problems need their own check. Microsoft's SNDS and JMRP programs give senders visibility and a delisting path.

Getting delisted at Microsoft

Microsoft's process is its own: you submit a delisting request through their sender support, and they expect the underlying issue fixed first. Authentication matters here more than most places, so confirm your authentication is clean before requesting removal.

How Nitrosend helps

Placement is measured against a first-party pool of about twenty real seed mailboxes that includes Outlook and Office 365, so Microsoft-specific problems show up in the data rather than as a mystery drop in one provider.

FAQ

What is a Microsoft blacklist check?

A check of whether your IP or domain is on Microsoft's own block list, which specifically affects delivery to Outlook, Hotmail, and Live addresses.

Why is my email blocked by Outlook but not Gmail?

Microsoft runs a separate reputation system. You can be clean on public blacklists and still blocked at Outlook, which needs its own check and delisting process.