The -c option allows one or more channel names to be specified. If present, checkque restricts its report to the named channels.
The -f option causes checkque to print the name of the oldest queued message for each channel. -p causes only channels with ``problems'' to be listed. Problems are defined as channels with mail waiting for over some ``problem threshold''. The default problem threshold is 24 hours. The -t option is used to change the problem threshold. A number of hours (or minutes, if m is appended) should appear without a space after the -t. -s forces an abbreviated summary listing instead of the normal multi-line report. -z causes channels with no messages queued to be skipped in the report.
checkque is distributed setuid to mmdf, which allows any user to inspect the queue. To restrict access to root and mmdf, use chmod(C) to turn off the setuid bit.
Many configurations will have only two channels. One is for local delivery and the second is for off-machine relaying, such as by dialup connections or by connections to ArpaNet hosts. Local delivery usually happens at the time of submission, so it is rare that any mail is waiting in it. Mail in other outbound queues is processed by deliver according to your site parameters, either by running deliver as a background daemon or by periodically invoking it via cron.
