Outlook.com
Microsoft's consumer email service, covering outlook.com, hotmail.com and live.com addresses, with its own postmaster site, SNDS data and JMRP feedback loop.
What it means
Microsoft describes Outlook.com as its consumer service supporting hotmail.com, live.com and outlook.com addresses. Its postmaster site serves administrators who send to it, with policies, troubleshooting and the SNDS portal, where IP owners see data about their traffic and enrol in the JMRP feedback loop.
Since May 5, 2025, domains sending more than 5,000 messages a day to Outlook.com must pass SPF and DKIM and publish DMARC (at least p=none) aligned with one of them, or face rejection with 550 5.7.515.
Outlook.com rejection messages carry Microsoft's own codes in the text, such as S3150 and SC-001, explained in the error code pages. Business mailboxes on Microsoft 365 are filtered by Exchange Online Protection instead.
Related terms
On this site
Sources
What this definition rests on. The wording is ours; the facts are theirs.
- Microsoft Tech Community: Outlook's requirements for high-volume senderstechcommunity.microsoft.com
- Outlook.com Postmastersendersupport.olc.protection.outlook.com
- Outlook.com Smart Network Data Servicessendersupport.olc.protection.outlook.com
All 432 terms in the glossaryThe wiki: blocklists and bounce codes