Deleting cells with same data as other cell

Hello,

I am trying to do the following in relation to two mailing lists in Excel.

1. Identify the email addresses in one list that are the same as in the other list.
2. Delete the email addresses in the first list that are the same.

One list is in Column A, the other in Column G in one work sheet.

Is there a formula or VB script to do this? Is there a way of doing the same task but just searching for part of an email address and deleting any duplicates?

Much appreciated.