First double check that your client settings match your server account settings. Please read about
Setting Up an FTP Client for more details on this. If your settings are fine then it is one of several possible setup problems:
You may have incorrectly configured your Domain Name Server (DNS) settings. Check that your domain name correctly points to your server's IP address.
You may have Antivirus software running on your server which is disrupting your FTP connections. It is recommended not to use client type Antivirus software on a server for conflict reasons like this.
