Sender-Initiated File Transfer (SIFT) protocol, also commonly called Unsolicited File Transfer (UFT) protocol is a file transfer protocol. It's method contrasts with other file transfer methods in that the sender need not have an account or any registration on the target host system, and the receiving user may have less steps to take to retrieve the file(s) sent. Unlike traditional file transfer, UFT lends itself handily to background or deferred operation, though it may be carried out immediately, even interactively.