EV:M CAgentExchSynch::ListMailboxesExchange2k - The mailbox (MBX Info) does not have an Exchange policy associated with it and will not be processed until it is added to a provisioning group
An Exchange mailbox is not assigned to a Provisioning Group in EV. Either the mailbox has never been assigned to a Provisioning Group, or at some point the accounts in Active Directory were moved to a different OU or Security Group preventing EV from properly provisioning it. This behavior is by design.
Ensure that the mailbox is assigned to a proper Provisioning Group in EV. Consider targeting the Whole Exchange Organization (if possible) to avoid future provisioning issues.