hi,
Just ran (again) into the following bug with j!mailalerts:
1. in back-end 'manage user subscriptions', unpublish a user (you do not want this user to receive the mailalert
2. cron is run and user gets email!

So it looks like the publish / unpublish setting is not taken into account when 'batch' sending mailalerts.

Only way to disable a user from receiving the mailalert is to either 'hack his account' and make the setting for him (which this person can undo) or hack the database and remove the 'frequency'

regards,
Ruud.