# Generates a thread consisting of a top level message and 'length'
# replies. The subject of the top message 'subject: top message"
# and the subject of the nth reply in the thread is "subject: reply n"
# Generates a thread consisting of a top level message and 'length'
# replies. The subject of the top message 'subject: top message"
# and the subject of the nth reply in the thread is "subject: reply n"