For the basics on how to send messages to investor users, you can refer users to this instructional video:
Subscription Packages are set to have a limit on the number of messages they can send in a 24 hour rolling period.
Message count doesn't reset at 12 midnight the following day, instead it refreshes 24 hours after the last message was sent.
All responses sent to an investor after they have reached to you doesn't count to your message limit.
To avoid confusion, timestamps on the Message Dashboard are shown in GMT.