If the server you want to connect to is an FTP server, then use the FTPS connection manager to connect to the server. If the server you want to connect to is an SFTP server, then use the SSH connection manager.
FTPS Connection Manager
If you are setting up a connection manager to access the remote server with the File Transfer Task and it is not working, there are several settings you can change to get it working.
Use the FTPS connection manager if the server you want to connect with is an FTP server. Using this connection manager gives you the option of using Implicit or Explicit SSL or TLS (TLS 1.2 is the most recent version of any of these).
If this is the correct connection manager for your situation, contact the FTP server administrator to find out which encryption protocol is used by the remote server. Is it SSL or TLS? SSL has evolved into TLS over the years so TLS is most likely the protocol you'll be using.
Once you have determined that, the other choice you need to make is whether it is Implicit or Explicit. Try Implicit if you have tried Explicit and vice versa. This determines the port that will be used, as well as whether both channels will be encrypted by default or whether it will be negotiated.
The choices for the FTPS connection manager are:
ImplicitSSL uses port 990
ExplicitSSL uses port 21
ImplicitTLS uses port 990
ExplicitTLS uses port 21
If you want a little more information about what these settings mean, read the following three paragraphs.
SSL and TLS use two channels to communicate. One channel is for commands and the other is for the data.
Implicit SSL/TLS uses port 990 by default and always encrypts both the command and data channels. This can slow down communication and use more bandwidth. Therefore, you may not want to use this if it's not necessary to encrypt everything. For instance, if all you need to encrypt is the user's credentials, these are sent on the command channel so you would not need to encrypt the data channel if the data is not confidential.
With Explicit SSL/TLS, the endpoints are allowed to choose whether to encrypt the data channel and/or the command channel. You can even choose to revert back to regular (unencrypted) FTP and not encrypt any channel at all. Explicit SSL/TLS runs over port 21, which is the same port used by regular FTP.
If the FTP server you want to connect to uses TLS 1.2, then you'll need to install SSIS+ 1.9 (or higher) to get support for TLS 1.2 in the FTPS connection manager. Older versions of SSIS+ do not support TLS 1.2 because it didn't exist when those versions were released.
SSH Connection Manager
If you want to connect to an SFTP Server, be aware that you will need to use the SSH connection manager. SFTP actually stands for "SSH File Transfer Protocol". The default port for the SSH protocol is port 22, although another port may be used. Check with the administrator for the SFTP server to determine which port to use.