Convert an email address to a valid, usable filename.
Convert a valid, usable filename to an email address, this only works if the filename contains _AT_ and _DOT_ strings.
Append a mail to the send queue, which will be driven by the CronSync service.
Supported timings can be found in ONO::Cron::CronSync::Bot, latest update:
1min 5min 10min 15min 30min 1hour 2hour 4hour
Each mail queue requires a config file, indicating the "Subject":
var/community/school/mail_queue/config/$queue.conf