Using Outlook 2013, I'd like to be able to view all header fields (RFC5322, not what Outlook calls headers) of a message that I preview in the reading pane.

Is there a setting, an option or a 3rd party add-on that do this or is there such a thing that can at least provide a right-click menu?

Edit: I do not need the raw message in whole, just the headers.


How do I view all header fields of a message that I preview in the reading pane?

The following procedure will set this up for you.


  • The PST file zize Will Increase as Outlook will store the message source in addition to storing the message's content
  • This means future emails will take up roughly double the space.

Make Available the Complete Message Source in Outlook

To set up Outlook so you can see the complete source of emails:

  • Press Windows-R
  • Type "regedit".
  • Hit Enter.
  • For Outlook 2016:
    • Go to HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­16.0\­­Outlook\­­Options\­­Mail.
  • For Outlook 2013:

    • Go to HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­15.0\­­Outlook\­­Options\­­Mail.
  • For Outlook 2010:

    • Go to HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­14.0\­­Outlook\­­Options\­­Mail.
  • For Outlook 2007:
    • Go to HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­12.0\­­Outlook\­­Options\­­Mail.
  • For Outlook 2003
    • Go to HKEY_CURRENT_USER\­­Software\­­Microsoft\­­Office\­­11.0\­­Outlook\­­Options\­­Mail.
  • Select Edit | New | DWord from the menu.
    • Select DWORD (32-bit) Value with 32-bit Office.
    • Use DWORD (64-bit) Value with 64-bit Office (which is unlikely).
  • Type "SaveAllMIMENotJustHeaders".
  • Hit Enter.
  • Double-click the newly created SaveAllMIMENotJustHeaders value.
  • Type "1".
  • Click OK.
  • Close the registry editor.
  • Restart Outlook if it has been running.

See the Complete Source of a Message in Outlook

Now you can retrieve the source of newly retrieved POP messages (editing the SaveAllMIMENotJustHeaders value does not restore the complete message source for emails that were already in Outlook):

  • Open the desired message in its own window.
  • Double-click the email.
  • Click FILE.
  • Make sure the Info category is open.
  • Now click Properties.
  • Find the source to the email under Internet headers:.
  • Click Close.

Source How to View the Complete Message Source in Outlook

  • 1
    I can see the mail headers using the procedure you outline (File-Info-Properties-Internet Headers) even without the registry key. My goal is to display those "Internet Headers" in the "reading pane" directly. – Jan Dec 7 '17 at 12:16

The following Macro displays the headers in a new mail message window (can't use a msgbox because of size limitations):

Sub ViewInternetHeader()
    Dim olItem As Outlook.MailItem, olMsg As Outlook.MailItem
    Dim strheader As String

    For Each olItem In Application.ActiveExplorer.Selection
        strheader = GetInetHeaders(olItem)

        Set olMsg = Application.CreateItem(olMailItem)
        With olMsg 
            .BodyFormat = olFormatPlain
            .Body = strheader
        End With
    Set olMsg = Nothing
End Sub

Function GetInetHeaders(olkMsg As Outlook.MailItem) As String
    ' Purpose: Returns the internet headers of a message.'
    ' Written: 4/28/2009'
    ' Author:  BlueDevilFan'
    ' //techniclee.wordpress.com/
    ' Outlook: 2007'
    Const PR_TRANSPORT_MESSAGE_HEADERS = "http://schemas.microsoft.com/mapi/proptag/0x007D001E"
    Dim olkPA As Outlook.PropertyAccessor
    Set olkPA = olkMsg.PropertyAccessor
    GetInetHeaders = olkPA.GetProperty(PR_TRANSPORT_MESSAGE_HEADERS)
    Set olkPA = Nothing
End Function

Source: https://www.slipstick.com/developer/code-samples/outlooks-internet-headers/

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.