However, you can still use this feature if your email client (the program you use to read your email) allows you to export your contacts list as a .csv, .vcf, or .txt file. Uploading this file to Facebook will allow us to use it to tell you which of your contacts are on the site. For more detailed instructions on how to do this with specific clients, please see the bottom of the Friend Finder page.
In the future, we hope to expand the feature's capabilities to serve the needs of a wider range of users. In the meantime, please feel free to utilize our other search and invitation tools.