If I use Extension FtpWebRequest with a username with normal characters, it works fine.
If I use a username that contains an @ in it (I tested it to connect to the same ftp server with ftpuser@myftpserver.com ), it returns "The remote server returned an error: (530) Not logged in."
(I connect with that user account to this server with other ftp clients)
Had the same problem...The extension uses (on different places) EncodeURL() for the username and Password... This doesn't work...
Just remove the EncodeURL() for Username and Password.
That should work fine.