request assistance - error code 4489

Question

I am receiving phishing emails, when I forward them to the company involved I get a microsoft message saying "couldn't deliver message"

Answer 1

If the email body contains phishing content, the recipient's email security can reject it.

If it is important to share this information with them, you can take screenshot, or download the internet header using this instruction: https://support.microsoft.com/en-us/office/view-internet-message-headers-in-outlook-cd039382-dc6e-4264-ac74-c048563d212c

Paste the email header to a Notepad file, save it as a txt file. Then right click and zip the file. Then send the zip file as an attachment instead.

Answer 2

Error code 4489 indicates a delivery failure. When forwarding phishing emails, the recipient’s mail system or Microsoft’s service is rejecting or not accepting the message, so Outlook returns a “couldn’t deliver message” non-delivery report.

To handle phishing messages in Outlook instead of forwarding them directly to the company:

1. Do not click any links, open attachments, or reply to the phishing email.
2. Use Outlook’s built‑in reporting:
   • In Outlook/Outlook.com, select the message and use the Report or Junk/Phishing option to report it. This sends the message to Microsoft for analysis and helps improve filters.
3. If the message appears to impersonate a known company and that company asks for reports, go to the company’s official website in a separate browser tab (do not use links in the email) and follow their published instructions for reporting phishing. If their system rejects forwarded mail, use any web form or instructions they provide instead of email forwarding.
4. After reporting, delete the phishing message.

If delivery failures continue for non‑phishing messages as well, review the full non‑delivery report (NDR) details in the “Diagnostic information for administrators” section of the postmaster message to see the exact reason and follow the suggested fix (for example, correcting the recipient address or reducing attachment size).

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References:

• Failed delivery messages from the postmaster at outlook.com, microsoft.com, or service.microsoft.com
• Phishing and suspicious behavior in Outlook
• Protect yourself from phishing