• Click the Tools menu, and click Remove.
• In the Mailing List Utility window, click the Browse button next to the Mailing List box, and locate a source Mailing List file.
• Click the Add button to add Remove List files to the list.
• Click the Browse button next to the Output Mailing List box, and specify the location and name of the output mailing list file.
• Click Start to begin the removal process.

This feature can also be used to process new address list against an old one.
For example: You have an old list of 10,000 addresses and you also have a new one containing 50,000. There may be duplicate addresses in both lists and you do not want to send the same recipient with same message twice.
You can resolve this problem by processing the new list file against the old one. When you click Start, you will have new file containing addresses that you have not used before.