1) advertise *.local and next_part near the top of the three scripts
2) daily: mention smtpd(8) mailq behaviour (like for sendmail, postfix, exim)
3) weekly: drop a comment trivially rehashing the next two lines of code
documenting next_part in the scripts was suggested by jmc@
ok sthen@ okan@ halex@; "i won't object" ajacoutot@