As per this blog's date, the FileZilla version is 18.104.22.168. You may see later version of FileZilla as you read this blog.
FileZilla is one of the well-known FTP client (and server) that has verbose output upon connecting to any FTP/SFTP server.
Sometimes, we may need to use older version of FileZilla to match the version that Akamai Customer use.
There are numerous options to obtain the old version of any program, including oldversion.com. However, due to the many reasons, it would be better to obtain the download direct from the source (a.k.a: the maker/ coder).
The common link to download FileZilla is FileZilla - Client Download
One of the link for Mac client is http://sourceforge.net/projects/filezilla/files/FileZilla_Client/22.214.171.124/FileZilla_126.96.36.199_macosx-x86.app.tar.bz2/download?nowrap
The link give us a hint that the list of FileZilla client download 'files' maybe found in http://sourceforge.net/projects/filezilla/files/FileZilla_Client
Guess what? It is!
Now you can have the privilege of getting old FileZilla version, which -hopefully- matched the same version that we intended to use for troubleshooting.