I am testing for a Transfer Target to an external SFTP server
I set the Endpoint Host as SFTP host IP, Endpoint Port as 22. However, there is no option for Endpoint Protocol for SFTP or FTP. There is only "http" or "https". Is my method correct?
Is there any way for content delivery to other FTP server for Alfresco? Thank you.
No I don't think so. The communication is based on webscripts which won't work over sftp. And alfresco doesn't provide an endpoint for sftp.
You could do something like copy the files from alfresco's inbuilt ftp server. For example filezilla can sync two ftp directories, but that's a very different process to the transfer service.