To increase security against password hackers we have locked down our FTP servers to only accept connections from authorized IP addresses. If you do not have a static IP address with your ISP then you may need to re-authorize your IP every time you use FTP.
To authorize your IP you can do any of the following:
Or, to authorize an IP in behalf of someone else (such as a web designer), use an 'ip' parameter like this:
http://example.com/cgi-tools/ftpallow?ip=192.168.1.1 (Replace 192.168.1.1 with the IP you want to authorize)
Most of these methods should have your IP authorized within 60 seconds or less. However, checking a POP box on your domain can take up to 5 minutes before your IP is authorized.
If your IP is not authorized then your FTP software may show this error upon trying to connect:
530 This FTP server is anonymous only.