- mailq [-sort] [-batch]
The optional -sort sorts the list according to the messages' timestamps, oldest messages first. This may take a while if the mail queue is very large.
The optional -batch uses an alternative, machine-parsable output format, one line per message:
Only the superuser can view the contents of the entire mail queue. Everyone else can only see their own messages.
The 80-column limitation forced a somewhat ugly design.