STOREDRIVER RECEIVE Events are not logging into Message Tracking Logs for User Mailboxes.

Hi,

I have one customer with exchange server 2013 Environment, when he sent a mail from the mailbox (STOREDRIVER, RECEIVE) events are not logged in Message Tracking Logs, but for System mailboxes we have a STOREDRIVER, RECEIVE events.

But he has events like (STOREDRIVER, DELIVER) for all the mailboxes.

Can you please advise me how to resolve it.

Thanks In Advance.