First off, completely brand new to all of this. I have been given the task at work to break down a csv file that is a dump of multiple users address books, and sorts them out according to the email addresses. What I'm looking to do is create a macro that would be able to distinguish a change in email address, and make a new file when it notices the change. Example:

A B
Data
Data
Data
Data

Ideally, I would like to create a file with the rows only in one file, followed by in another file, using the same macro if possible. Not sure if this is even something that can be done, but I figured I'd take the shot considering the Excel file I have has over 300 address books and 6000 columns. Thanks in advance for any advice or suggestions!