How to transfer a .txt file from windows to unix using FTP?
Yes…you can do it via pub.client:ftp service to transfer files from local to remote site.
Please have browse the built in services user guide regarding WmPublic package foldercalled pub.client.ftp (there are FTP related services for login,cd,put,logout)
Also you can use the search functionality of this particular section for any basic questions.
HTH,
RMG
Without using built in service, how can we place an attachment of file in unix server using FTP commands?
You can google it… 
for unix command line steps: