UUCP provides two daemons (uucico and uuxqt) which establish communication sessions, transfer data, and execute commands according to the requests scheduled by uucp (for file exchange) and uux (for command execution). uux will invoke uucico unless the command is a local one, in which case it will invoke uuxqt to process the local command immediately. While you can invoke these daemons interactively as the need arises, this becomes inconvenient if many users become dependent on UUCP's capabilities, or if the system must receive data from other UUCP systems according to some regular schedule.

It is also used to initiate work on behalf of others at predefined times. A crontab file defines the work to be done for a user and the schedule for running it. Use the crontab command to create the crontab file. After a user creates a crontab file (assuming that the cron facility has been configured by the administrator), cron initiates the work according the schedule specified.

If the UUCP daemons are running from cron and encounter an error, they send mail to the user who ran the uucp or uux command that the daemons are processing. The daemons log their status and errors in two files: /usr/spool/uucp/ERRLOG is used to log errors and /usr/spool/uucp/LOGFILE is used to log non-error status. Check those files if the daemons uucico or uuxqt do not seem to be running correctly.