From Debian: UUCP is used to transfer mail, news and random files between systems which are not connected by more modern networks. The communication can be made via modems, direct (hard-wired) serial connections or via an IP connection.
From Wikipedia: UUCP is an abbreviation for Unix-to-Unix Copy. The term generally refers to a suite of computer programs and protocols allowing remote execution of commands and transfer of files, email and netnews between computers. Specifically, UUCP is one of the programs in the suite; it provides a user interface for requesting file copy operations. The UUCP suite also includes uux (user interface for remote command execution), uucico (communication program), uustat (reports statistics on recent activity), uuxqt (execute commands sent from remote machines), and uuname (reports the uucp name of the local system).
# make menuconfig
Package Selection for the target ---> Networking ---> [*] uucp