This setting describes how to set the max setting on Calendar items based on how many how many items you want to rewrite per email. By default it will will rewrite all the the address, but for messages with over say several hundred recipients that my be too time consuming.
First go under the:
You need to create a maxAddressRewrite and set to the Maximum number of Address you want rewritten. This will be the decimal value will be the max value.
Then when you run the Migrator, it should say if this key has been set in the log you should see the following entry in the log file:
Migrator Version : MessageOps Exchange Migrator
MaxAddressRewrite set to 15