How To Activate Visitors Messages for all members By query ( SQL)

[4nawadir.com]

Hello, How are you ?

when i create my forum i was disable visitors messages
Today i enable it ,
But members should activate it in their usercp
I need an query (SQL), To activate it to all members
Because member sould cheack (activate visitors messages) in their usercp - one by one -
Like this picture

Question: How to activate cheack for all members

Thank You