email rejecting safe sender

AS9031519 is a server-level rejection that Safe Senders cannot override; each affected sender must give the complete non-delivery report to their email provider or domain administrator for investigation of the sending domain’s SPF, DKIM, and DMARC authentication.

The rejection occurs while the sending server is handing the message to Microsoft, before it reaches your Outlook.com mailbox. Safe Senders only affects messages that Outlook.com has already accepted, so adding the address again will not resolve this case.^1^

What to do

1. Ask one affected sender for the complete bounce message, also called the non-delivery report (NDR). It should include:
   • The SMTP status, such as 550 5.7.x
   • All text immediately before and after AS9031519
   • The Microsoft server name, timestamp, and diagnostic details
2. Have the sender forward that report to their email administrator or provider. The administrator should check:
   • SPF authorizes the server that transmitted the message.
   • DKIM signing is enabled and validates.
   • DMARC exists and aligns with the domain shown in the message’s From address.
   For example, an SPF failure means the transmitting server was not authorized by the sender domain’s SPF DNS record; that must be corrected by the sender or its provider.^2^
3. After the sender corrects the authentication or sending-server problem, have them send a new test message. The previous rejected message will not appear automatically.

Your personal @outlook.com address does not need SPF, DKIM, or DMARC records configured by you—Microsoft manages the Outlook.com domain. The authentication details in this rejection concern the sender’s domain.^3^

If the sender says authentication passes

The sender or their mail administrator should use Microsoft’s Outlook.com Sender Support guidance to examine sending-IP reputation, reverse DNS, and other server-side delivery requirements. Microsoft also provides an issue-submission route there for compliant senders whose messages remain blocked.^4^

If unrelated senders are all affected

If messages from several unrelated providers or domains produce the same rejection:

1. Sign in to Outlook.com.
2. Select Help from the top menu.
3. Search for the issue.
4. At the bottom of the Help pane, under Still need help?, select Yes.
5. Include complete NDRs from two or more affected senders, including timestamps and SMTP codes.^5^

Do not post the complete reports publicly without removing email addresses, message IDs, and other identifying information.

References

1. People who send me email are getting blocked saying they aren't from a ...
2. Not receiving most emails all of a sudden - Microsoft Q&A
3. Incoming emails being blocked due to lack of SPF/DKIM/DMARC records on my @outlook.com account - Microsoft Q&A
4. Sender Support in Outlook.com | Microsoft Support
5. How to get support for Outlook.com | Microsoft Support