Have you also tried with the command-line FTP? If not, please do so and send a screenshot.
Could you please tell us how you produced the FTP log below? (What software did you use?)
If FileZilla and the command-line FTP work fine, but not your program, (also considering our FTP service has been around for over a decade), I believe it is caused by a bug in your code. There are many free FTP client codes and libraries you can use instead of directly programming Sockets.
Looking at your FTP log:
-----------------------------------------
Host IP Address=66.220.9.50
Socket Opened=372
Response: 220 Welcome to the most popular FTP hosting service! Save on hardware, software, hosting and admin. Share files/folders with read-write permission. Visit http://www.drivehq.com/ftp/;
Command: USER lJzpGw3vWfwT
Response:
Command: PASS ************
Response:
Socket Closed
------------------------------------------------------------------------
You can see that your program did not even receive the first response (to the USER command). This could be caused by:
(1) Your account was blocked. But if you can connect via FileZilla, then your account is (was) not blocked. FYI, free accounts are limited to log on 25 times per day. Anyway, you might want to try with a different account. (You can test with your Group main account), or you can order our monthly service.
(2) Your program did not send the correct command, e.g. it did not flush the data after sending USER lJzpGw3vWfwT, in this case, our server did not receive your command at all; or it did not end with <CRLF> (e.g. did you only use <CR> or <LF> ? )
If this is for an enterprise account (project), please call our support line. We will have a senior engineer to help you, even though it is not a DriveHQ FTP server issue.