IIS 7.5 FTPS external access - 534 Policy requires SSL

Solution 1:

You're correct that FileZilla or WinSCP are needed. Basically those FTP settings say that anyone trying to use the normal method over port 21 should be denied, and it doesn't attempt to reestablish a different type of connection. Thus IE and the command line options won't work.

A good test is to install FileZilla locally on the FTP server, or on another server that doesn't have a firewall in-between. Get it working there to prove that it works, and then start looking at your firewall policy to allow it through. Most likely you're running again a firewall rule that blocks the dynamic ports necessary for FTPS.

In FileZilla, use "explicit FTP over TLS" and test using active and passive mode. Active and passive require different firewall ports.

Solution 2:

To confirm: You need a client that supports FTPS. WinInet in Internet Explorer, and Windows' command-line FTP.EXE do not.