WinZip Courier allows you to choose between two different compression methods when it creates Zip files. This information is provided to help you understand the differences between the two methods and to give you the information needed to choose one or the other.
Zip: Legacy (Compatibility)
The Legacy method uses a traditional data compression algorithm, known as 'deflate', that is supported by all versions of WinZip and virtually all other Zip file utilities. The 'deflate' method is generally considered to be a good all-purpose compression algorithm for most types of files. Legacy is your best choice when your mail recipient's Zip utility is unknown, or known to use older technology. By default, legacy compression creates a Zip file with the extension '.zip'.
Zipx: Best method (smallest size)
The Best method option allows WinZip Courier to choose the best compression method for each file, based on the file type. You may want to choose this option if compressed file size is a primary concern. Be sure that the recipients of your e-mail are using WinZip 12.0 (or later) or another Zip file utility that is compatible with all of WinZip 12.0's compression methods. By default, best method compression creates a Zip file with the extension '.zipx'.