1) How I check if a file to be transferred already was sent ?
It's sent when the put command finishes or when a whole script finishes. ... BOTH CASES
That was not a question. That was a statement. A transfer is complete once the
putcommand finishes. What do you want to check?
2) How I check if file is shipping and get everything ? ... Transferred or Send
What does it mean "file is shipping"?
Sorry, can you be more specific? What's the difference between 1) and 2)?
3) How can I send a message to the ftp server ?
What message? ... I end the process good
Again, this is quite vague. There's no way to send a "message" to an FTP server. If the FTP server expects some kind of indication about completed transfer, it has to have it's specific and defined way to do so. We cannot know that. Ask your server administrator.
You may want to read https://winscp.net/eng/docs/script_locking_files_while_uploading