You can test rewrite rules with the imsimta test -rewrite command. The -noimage qualifier will allow you to test changes made to the configuration file prior to recompiling the new configuration.
You may find it helpful to rewrite a few addresses using this utility with the -debug qualifier. This will show you step-by-step how the address is rewritten. For example, issue the following command:
For a detailed description of the imsimta test -rewrite utility, see the Sun Java System Messaging Server 6.3 Administration Reference.