Emails sent to my MSN account are being returned as undeliverable.

Question

Some emails sent to my MSN account are being returned to the sender as undeliverable, but most senders are not having this problem. Is the problem on my end or with the sender? What is the solution?

Answer 1

Hi. I'm Brian.

When the person sending you the message receives the non-delivery report, the reason why the message couldn't be delivered will be in that report. If you know someone who received a non-delivery report, ask them what the report says.

Answer 2

This can be either side, depending on what the sender’s bounce message says.

Most commonly, if only some people cannot send to an MSN/Outlook.com address, the sender should check the non-delivery report they received. Common causes include:

• invalid or outdated recipient address
• the sender’s message being flagged as spam
• the sender’s mail server having delivery problems
• the sender’s system being blocked or failing authentication

Checks on the MSN/Outlook.com account side:

1. In Outlook.com, check Junk Email settings and the Junk Email folder.
2. Check Mail > Rules for any rule that could redirect, block, or hide messages.
3. Check whether Forwarding is enabled and remove any incorrect forwarding target.
4. If using a third-party mail app or service, disable IMAP/POP temporarily and test again.
5. If messages are not visible, check Other and restore sorting with Filter > Sort > Date.

Checks for affected senders:

1. Ask the sender to read the bounce message, especially the Diagnostic information for administrators section.
2. Confirm the MSN address is typed correctly.
3. If the sender is replying from Outlook desktop, have them remove the saved AutoComplete entry for the address and type it again manually.
4. If the sender’s message contains links or attachments, have them send a plain-text test message first.
5. If the sender gets a spam-block or authentication-related NDR, the issue is on the sender side and they may need to use Sender Support for Outlook.com.

If only certain senders fail while most others succeed, that usually points to a sender-side issue rather than a problem with the MSN mailbox itself.

---

• Can't send or receive email in Outlook.com
• Failed delivery messages from the postmaster at outlook.com, microsoft.com, or service.microsoft.com
• Can't send or receive email in Outlook.com
• Sender Support in Outlook.com
• emails undeliverable - Microsoft Q&A Remote server returned '554 5.7.0 < #5.7.520 smtp;550 5.7.520 Message blocked because it contains content identified as spam. AS(4810)>'