Mam naprosto stejny problem:

ftp srv50.endora.cz
Connected to srv50.endora.cz.
421 Service not available, remote server has closed connection

ftp srv40.endora.cz
Connected to srv40.endora.cz.
220 FTP Server ready.
Name (srv40.endora.cz:user):

Hadejte na kterem serveru mam ucet