Private Message enabling for certain users only

[Megatr0n]

Is there a hack which allows you to enable pvt messaging to those users who have hit a particular post count?

[nexialys]

1- deactivate the PM for all your existing usergroups
2- create a usergroup with PM activated
3- create a promotion where users will join that usergroup when they hit X posts

all your users will be updated when the hourly cronjob is passed.