Implicit FTP (port 990) not working

Symptoms

When connecting to Implicit FTP (port 990) the connection may be refused or timeout.

Description 

Implicit FTP is not supported by cPanel. The is discussed further in the forum post below.

https://forums.cpanel.net/threads/creating-sftp.142921/#post-659449

Workaround

FTP can be set to require encryption in the following location of WHM.

Home » Service Configuration » FTP Server Configuration