Windows Mail stores the account specific settings such as Message Rules, Junk Mail options etc, under the following registry key and its sub-keys:
To backup the Message Rules, follow these steps:
Click Start, type Regedit.exe. Navigate to the following key:
From the File menu, choose Export and save the branch to a .reg file.
Exit the Registry Editor.
Block Senders List & Safe Senders List
The Safe Senders and Block Senders list are stored in two separate sub-keys (Block Senders List & Safe Senders List) under the following key: