If you're moving to a new system or doing a clean install, the {...} numbers are be different and you may have to manually move the entries to the differently numbered entries that are actually being used.

How to do this? This is the method that we use in our office:

1. Export the registry branch on the old PC to a *.reg file.
2. Transfer this "reg" file to the new PC
3. On the new computer search for the (still empty) settings of your new Outlook Express installation. Once you find, you have the new {...} number!
4. Now, open the transfered*.reg file with a text editor and make a "Search and Replace": 
Replace the old {....} value with the NEW {...} that you just located in the registry. 
5. Save this file and then click on it. This will import your old settings in the NEW registry. 

5. Passwords

Outlook Express, along with those of most other Microsoft applications such as Internet Explorer, stores its passwords in .PWL files in your Windows directory. There's a separate file for each username on the system. Backup the files frequently.