It is used in function to populate mail-box scroll-list items.
Code:
control:RegisterForEvent(EVENT_MAIL_READABLE, function(_, mailId) manager:OnMailReadable(mailId) end)
control:RegisterForEvent(EVENT_MAIL_TAKE_ATTACHED_ITEM_SUCCESS, function(_, mailId) manager:OnTakeAttachedItemSuccess(mailId) end)
control:RegisterForEvent(EVENT_MAIL_TAKE_ATTACHED_MONEY_SUCCESS, function(_, mailId) manager:OnTakeAttachedMoneySuccess(mailId) end)
...
dataTable.isReadInfoReady = IsReadMailInfoReady(mailId)
isReadInfoReady is used to enable keybind-button.