Also, not all servers support ASCII mode despite the fact that they support version 4 of SFTP protocol. So it can be that you should convert the file locally in your code before sending or after retrieving the file.
ASCIIMode property doesn't seem to work. What's wrong?
Text mode is supported by SFTP protocol versions 4 and later. To ensure, that the connection is established using SFTP 4 or later you need to enable SFTP 4, 5 and 6 and disable SFTP 1, 2 and 3 using Versions property of ElSimpleSftpClient or ElSftpClient components. See documentation for information about how to set Versions property in ElSimpleSFTPClient and ElSftpClient.