Your emails land in Outlook or Hotmail junk

What it means

Microsoft's consumer mailboxes (Outlook.com, Hotmail, Live, MSN) put your email in the Junk folder, or sometimes refuse it. Microsoft relies a lot on the reputation of your sending IP address, plus authentication and the reactions of its users.

Business mailboxes hosted on Microsoft 365 use a similar filter, but each company can add its own rules.

Why it matters

Outlook and Hotmail are among the largest email services in the world. Since 2025, Microsoft also asks high-volume senders to have SPF, DKIM and DMARC, like Gmail and Yahoo.

How to check

• Send a test email: on the home page, copy your unique test address, send it a normal email from the mailbox or tool you want to check, then open the report. Check authentication, blacklists and reverse DNS.
• Look at the bounce if the email was refused. Codes such as 550 5.7.1 with "S3150" or "banned sending IP" mean your IP is blocked by Microsoft.

How to fix it

1. Fix the basics. SPF, DKIM and DMARC must pass for your domain, and your server must have valid reverse DNS. Use /domain-scanner to check your records.
2. Check blacklists at /blacklists. Microsoft uses its own lists, but a listing elsewhere is often a sign of the same problem.
3. Sign up for SNDS (Smart Network Data Services, free). It shows, for IPs you own, how much email Microsoft received and how much was flagged as spam. It only helps if you have your own server or a dedicated IP.
4. Join JMRP (Junk Mail Reporting Program, free). Microsoft sends you a copy of each email a user marks as junk, so you can remove those people from your list.
5. Request a review if your IP is blocked: use the Microsoft sender support delist portal and give the IP address. Explain briefly what you fixed.
6. Improve your list and content: only email people who opted in, remove bounces and inactive contacts, and make unsubscribing easy.

If you use a shared provider

If you send through Microsoft 365, Google Workspace or a newsletter tool, the IP is not yours. SNDS and the delist portal are for the IP owner. Fix authentication and content on your side, and contact the provider's support with your Delivmail report if the problem continues.

Ask people to help

Recipients can click "Not junk" and add you to their Safe senders list. It helps for that mailbox and is a positive signal for Microsoft.

Check that it is fixed

Send a new test email from the home page: authentication, blacklists and reverse DNS should all be clean. Then send to a test Outlook.com address. Reputation improves over days or weeks of clean sending, so follow the trend in SNDS if you have access.

Microsoft tools: SNDS and JMRP and the delist portal.