Install this extension on your wordpress site.
Then you can visit the plugin page, and activate it "Contact Form 7 to DB Extension". There is a settings link there on the same plugin activation page.
It logs all the fields into a mysql database table.
On the same plugins page in WP, it will has a link beside "Contact Form 7 to DB Extension" which says "Data"
That link shows all the data/information submitted in your forms from wordpress.
From the data page you can then export to Excel, see the rows, delete the rows, etc.
In Excel (I used verison 2010) it will open, and prompt you to Enable (security warning) then you can type your wordpress username and password. You can click the data tab hit the Refresh button and it will dynamically query that mysql table using the login and password you saved. Save the Excel file on your computer documents, and just open the Excel file in the future and do the data tab > refresh (F5) to get updated data from the WordPress server.