Our servers support FTPS (Encrypted FTP) rather than plain FTP (unencrypted - the communication between the server and client is in clear text and can be easily intercepted and compromised). FTPS uses Transport Layer Security (TLS) / Secure Sockets Layer (SSL) connections to encrypt data transferred over FTP control and data connections.
To use FTP over TLS (FTPS) you need a TLS capable FTP client.There are many free FTPS clients available, Filezilla (https://filezilla-project.org/) being one of them.
Instruction to use FTPS with Filezilla. If you are using the Quick connect dialogbox, prefix the hostname with ftpes://
If you are using the Site Manager, select ServerType as FTPES from the dropdown.