Not receiving email in Outlook from one email address

Check Outlook on the web first, remove the address or its domain from Blocked senders, and add it to Safe senders; if the message still does not arrive, the sender’s delivery error or an administrator message trace will identify where it was rejected.

1. Check the mailbox in Outlook on the web

Using the web mailbox distinguishes a mail-delivery problem from an Outlook desktop synchronization problem.

1. Sign in to Outlook on the web and select the correct account.
2. Check:
   • Junk Email
   • The Other tab, if Focused Inbox is enabled
   • Deleted Items
3. Select Settings → Mail → Junk email.
4. Under Blocked senders and domains, remove the sender’s complete address and domain if either appears.
5. Under Safe senders and domains, add the sender’s complete email address.
6. Review Settings → Mail → Rules and disable any rule that deletes, redirects, or moves messages from this sender.
7. Check whether forwarding is enabled.
8. Ask the sender to send a new test message with a distinctive subject.

Microsoft recommends checking Junk Email, the Other tab, forwarding, and inbox rules when a specific Outlook.com message is missing.^1^ Adding an address to the Safe Senders list tells Outlook that messages from that sender should be trusted.^2^

2. Ask the sender for the delivery result

Have the sender check for a non-delivery report (NDR) or bounce message and send you the complete error text.

• No bounce message: If this is a Microsoft 365 work or school mailbox, ask the administrator to run a message trace.
• Authentication error, such as 550 5.7.515: The sender or their email administrator must correct the sending domain’s authentication configuration. Adding them as a safe sender might not help when Microsoft rejects the message before it reaches your mailbox.^3^
• 5.7.511 Access denied or “banned sending IP”: The sender must use Microsoft’s sender delisting portal at https://sender.office.com, enter the address that received the NDR and the sending IP shown in it, complete verification, and request delisting.^4^

For urgent communication, ask the sender to use another email address until the sending-system problem is corrected.

3. For a Microsoft 365 business mailbox

A Microsoft 365 administrator should trace a fresh test message:

1. Open Microsoft 365 Admin → Exchange.
2. Go to Mail flow → Message trace.
3. Choose the test message’s date range.
4. Add the exact sender and recipient addresses.
5. Select Search, open the result, and inspect Details and How to fix it.

The result establishes the next action:

• Delivered: Check inbox rules, forwarding, Junk Email, and Outlook synchronization.
• Quarantined: Open Microsoft Defender quarantine, locate the message by sender or recipient, and release it if it is legitimate.
• Failed or blocked: Use the detailed rejection reason; it may require changing a mail-flow/security policy or having the sender correct their mail system.
• No result: The message probably did not enter the organization; obtain the sender’s NDR and message details.

Microsoft documents message trace as the administrator tool for following a message through Exchange Online and determining whether it was delivered, filtered, delayed, or blocked.^5^ Administrators can also filter quarantine by sender, recipient, subject, or time and release legitimate messages.^6^

References

1. Can't send or receive email in Outlook.com | Microsoft Support
2. Options > Junk Email | Microsoft Support
3. Why am I not receiving emails from certain senders that I haven't blocked? - Microsoft Q&A
4. Can't receive emails from certain senders - Microsoft Q&A
5. Find and fix email delivery issues as a Microsoft 365 for business admin
6. Manage quarantined messages and files as an admin