How to View the Complete Email Message Source in Outlook

Display message headers and find out the source of your incoming email

What to Know

  • Open Registry Editor. Go to Windows Search, type regedit and press Enter. Go to the Windows Registry folder.
  • In the Edit tab, select New and choose either Dword (32-bit) or Qword (64-bit).
  • Enter the name SaveAllMIMENotJustHeaders and press Enter. Double-click the name value. In the value data box, enter 1. Press OK.

This article explains how to enable the complete message source in Outlook email messages. It includes information on how to then view the complete source of specific emails as they arrive. Instructions in this article apply to Outlook 2019, Outlook 2016, Outlook 2013, Outlook 2010, and Outlook for Microsoft 365.

Configure Complete Message Source Availability in Outlook

Outlook takes messages it receives from the internet and stores the headers and individual message parts independently from the message body. When you select a message, Outlook collects the pieces to show just what is needed. Except when you want Outlook to display the headers. By default, Outlook removes certain header lines. Here's how to configure Outlook to preserve the complete source of email messages.

  1. Open Registry Editor. Go to the Windows Search box, enter regedit, and press Enter. Or, right-click the Windows Start button, select Run, enter regedit, and select OK.

    regedit in Search box in Windows 10
  2. Navigate to the folder of the Windows Registry for your version of Microsoft Outlook:

    Outlook 2019 and 2016:

    HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­16.0\­­Outlook\­­Options\­­Mail.
    

    Outlook 2013:

    HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­15.0\­­Outlook\­­Options\­­Mail
    

    Outlook 2010:

    HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­14.0\­­Outlook\­­Options\­­Mail
    

    Outlook 2007:

    HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­12.0\­­Outlook\­­Options\­­Mail
    

    Outlook 2003:

    HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­11.0\­­Outlook\­­Options\­­Mail
    
    Registry Editor
  3. Go to the Edit tab, select New, then choose either DWORD or QWORD:

    • Choose DWORD (32-bit) Value if you have a 32-bit version of Office.
    • Choose QWORD (64-bit) Value if you have a 64-bit version of Office.
    Edit > New in Registry Editor
  4. To name the value, enter SaveAllMIMENotJustHeaders and press Enter.

    SaveAllMIMENotJustHeaders
  5. Double-click the SaveAllMIMENotJustHeaders value.

    Value dialog
  6. In the Value data text box, enter 1, then press OK.

    Vale Data
  7. Close Registry Editor.

  8. Open Outlook. If Outlook is open, close and then re-open it.

Outlook stores the message source and the message content. This means that future emails will take more space. Because PST files (where Outlook stores mail) have a size limit, regularly delete or archive email in Outlook.

See the Complete Source of a Message

Editing the SaveAllMIMENotJustHeaders value does not restore the complete message source for emails that were already in Outlook. To retrieve the source of newly retrieved POP messages

  1. Open the desired message in a separate window.

  2. Go to the File tab and select Info.

  3. Select Properties.

    Info tab on message File window
  4. To find the source of the email, look in the Internet headers section.

    message properties
  5. Select Close when you're finished.

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