Is there any plugin for limiting PMs in a particular time and the whole PMs a member can consume or there's a built-in setting?
Let me know please
Total number of private messages
1. Go to Admin CP > Users & Groups > Users > Select a Usergroup > Users and Permissions > Private Messaging > Message Quota.
2. Enter the number of total private messages.
Limiting PMs in a particular time
http://mods.mybb.com/view/limit-number-of-pms