On the Contacts tab you can use the 
icon in order to export the your contacts data. The contacts will be exported to a CSV file which can be opened by Excel or Open Office Calc. The data from this file can used for mailings or any other updates needed.
The customer lists can be exported completely without the use of filters. You can also export the file with a filter, for example, by keyword, contact. The export is performed according to the filter previously set. If you, for example have previously filtered all guests with the title “Newsletter” (How do I collect the files referred to from keywords?), when you make the export you will see just this in the CSV file you exported, but it is available for processing if needed.
Depending on your browser and settings you have, the CSV file is ready for viewing.
Open and save the file accordingly for further processing. If special characters are not displayed correctly, please see the follwoing article: How do I save the contact import file CSV coded as UTF-8?