The FTP server is running with the user exit FTCHKPWD. The client was attempting to log in to the FTP server as an anonymous user and was prompted for an email address. The user exit does not allow the user to access the FTP server with the email address that was entered.
FTP continues. The client login is rejected.
Contact the owner of the FTP server to have the email address authorized in the FTCHKPWD user exit.
If necessary, update the FTCHKPWD user exit to authorize the email address.