BuddyPress Message Reply Restrictions section allows you to configure restrictions for your site members reply to their messages.
Here is a screenshot showing Message Reply Restrictions.
1. Restrict Message Replying? You can use it to enable or disable the message replying restrictions. All other messages replying restriction options are only applicable if it is enabled.
2. Who can reply? This option lets you restrict the message replying by the user role.
3. Message shown to replied:- Set a default notice for users who is not eligible for the reply.
4. Apply threshold limit? This option allows you to set a maximum limit on the number of messages allowed. You can disable to set no limit for the allowed roles.
5. How many reply a user can make:- If threshold is enabled, this is the maximum number of relies allowed.
6. Apply duration? You can either set a limit for the lifetime or use this option to apply the limit for a certain duration. It allows you to setup a rate limiter like 20 messages per day.
7. During the time(in minutes):- If apply duration and threshold is enabled, it allows you to setup the duration after which the limit will be reset.
8.Notice to shown when the threshold limit reached:- Set a default message to showing a user after threshold time out.