In Exchange Server 2010 the Exchange Management Console doesn’t provide a way to visually locate mailboxes that have no storage quota, or mailboxes that have a non-standard storage quota configured. However you can find mailbox storage quota settings quickly using the Exchange Management Shell.
To list all Exchange Server 2010 mailboxes that are exempt from the mailbox database storage quota settings use this command in the Exchange Management Shell.
get-mailbox | where {$_.UseDatabaseQuotaDefaults -eq $False}
To Set al mailbox to Mailbox Database Default:
get-mailbox | where {$_.UseDatabaseQuotaDefaults -eq $False} | set-mailbox -UseDatabaseQuotaDefaults $true