RSSApplies to Microsoft Outlook 2013, Outlook 2010, Outlook 2007, Outlook 2003
Beginning with Outlook 2003 you can view the header and message source code source together in the options dialog, provided you edit a registry key.
This works on mail downloaded from Internet mail transports only, meaning it works with POP3 and IMAP accounts only (and EAS in Outlook 2013), not Exchange server mailboxes or Outlook Connector accounts.
To learn how to open the Message options dialog so you can view the Internet Headers, see How to View Internet Headers
Note that setting this registry value will result in larger messages stored in your data file. For this reason, you may want to use this key only when you need to troubleshoot issues. If you delete the key (or change the value to 0), the source code will not be removed from messages already downloaded.
Set the SaveAllMIMENotJustHeaders registry value
Open the registry editor and navigate to the correct key for your version of Outlook, then right click on Mail in the right pane and choose new DWORD, naming it SaveAllMIMENotJustHeaders. Set a value of 1.
Outlook 2013
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Options\Mail Parameter: SaveAllMIMENotJustHeaders Value: 1
Outlook 2010
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Options\Mail Parameter: SaveAllMIMENotJustHeaders Value: 1
Outlook 2007
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Options\Mail Parameter: SaveAllMIMENotJustHeaders Value: 1
Outlook 2003
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\Options\Mail Parameter: SaveAllMIMENotJustHeaders Value: 1
After editing the registry, restart Outlook then view the message headers of messages that were downloaded after you restarted Outlook.
Do It For Me
Download the correct file for your version of Outlook, then double click to add it to the registry.
Outlook 2013 Outlook 2010 Outlook 2007 Outlook 2003
Remember: This works only with POP3, IMAP, and EAS accounts and only for messages not yet downloaded. To view the source for POP3 accounts where messages are left on the server, create a second account in Outlook and re-download the messages.
