Several users wanted to block mail coming from the top-level EU domain but “EU" isn't among the TLD's listed in International , Blocked Top-Level Domain List.
While you can’t change the Blocked Top-Level Domain list, you can block EU (and UK, which is also missing). The International TLD’s that are in the Junk Email filter are stored in the registry under the Outlook profile key and it’s editable.
Before you edit the registry, make sure at least one domain is on the list in Junk Email Options, International tab, Blocked Top-Level Domain List if using Outlook 2010 or 2013; look in Tools, Options, Junk Email in Outlook 2007 and 2003.
This adds the value to the registry so it’s ready to edit. You should add all domains you want to block before editing the registry, as adding more later will remove EU. Each account in Outlook 2010 and Outlook 2013 have their own Junk Email Options and you’ll need to set it up for each account you want to add EU to.
If you’re using Outlook 2013, the profile is stored at HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Profiles\
Anyone with Outlook 2010, 2007, or 2003 will have the profile at HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows Messaging Subsystem\
In Outlook 2013 and 2010, the International blocked domains list is stored in a separate key for each email account in the profile. Search for 001f0424, you’ll find it under a different key for each email account that blocking at least one TLD. In Outlook 2007 and 2003, it’s in the 0a0d020000000000c000000000000046 key, also in value 001f0424.
This is a binary value. The easiest way to edit it is to add a TLD to the list that you don’t want blocked (such as ES) then select the individual letters to change them, one at a time. Remove the letter by backspacing over it then type in E or U (or just U, if you use ES).
Remember: If you add countries to the list using the Junk mail interface, you’ll need to re-edit the registry.
For detailed instructions and a video tutorial, see Add EU to the International TLD blocked list
Published August 7, 2014. Last reviewed on August 7, 2014.