The professional tool to automate FTP, SFTP, FTPS

and schedule FTP batch jobs

Missing any feature or command? Post your ideas here. Suggestions are welcome.
Sometimes it is not possible to upload a file because it is in use.
The PUTFILE command should have a parameter specifying how many time it should retry.

I cannot use the error handling logic for this, because there would have to be such logic for each file - too messy.

Yes, this is something that is already on the wish list. The problem you described have been alerady reported by other users.

Now I am working on automatically resuming file transfers on very large files (1-2GB) which sometimes fails. As soon as I finish this I will try to find a solution to this.