Within the contrib directory exists a utility with the descriptive (if compact) name of sendunsentbugmail.pl. The purpose of this script is, simply, to send out any bug-related mail that should have been sent by now, but for one reason or another has not.
To accomplish this task, sendunsentbugmail.pl uses the same mechanism as the sanitycheck.cgi script; it scans through the entire database looking for bugs with changes that were made more than 30 minutes ago, but where there is no record of anyone related to that bug having been sent mail. Having compiled a list, it then uses the standard rules to determine who gets mail, and sends it out.
As the script runs, it indicates the bug for which it is currently sending mail; when it has finished, it gives a numerical count of how many mails were sent and how many people were excluded. (Individual user names are not recorded or displayed.) If the script produces no output, that means no unsent mail was detected.
Usage: move the sendunsentbugmail.pl script up into the main directory, ensure it has execute permission, and run it from the command line (or from a cron job) with no parameters.