When a remote computer calls your computer and completes its work, the remote computer can attempt to retrieve the work that your computer has queued for it. The SENDFILES option specifies whether your computer can send the work that is queued for the remote computer.
The string SENDFILES=yes specifies that your computer can send the work that is queued for the remote computer if it is logged in as one of the names in the LOGNAME option. This string is mandatory if you have entered Never in the Time field of /etc/uucp/Systems. This designation sets up your local machine in passive mode, but it is not allowed to initiate a call to this particular remote computer. See UUCP /etc/uucp/Systems File for more information.
The string SENDFILES=call specifies that files that are queued in your computer are sent only when your computer calls the remote computer. The call value is the default for the SENDFILES option. This option is only significant in LOGNAME entries because MACHINE entries apply when calls are sent to remote computers. If the option is used with a MACHINE entry, the option is ignored.