I'm wondering if there is a way to see a log of all Exchange 2007 quota warnings. Is there a way to do this?
AFAIK these are not logged anywhere other than via the warning message sent to individual mailboxes. It'd be fairly trivial to script this though and determine which mailboxes are over quota. Loop through your mailboxes, do a Get-MailboxStatistics, and compare the TotalItemSize property to the WarningQuota property on the mailbox.