We recently upgraded from Exchange 2013 CU5 to Exchange 2013 CU7. Our IIS log files for 'Exchange Back End' have increased from ~25MB per day to >400MB per day. Does anyone know why the dramatic increase?

Never mind. I answered my own question. These were mailbox servers that only held passive database copies until the upgrade. We activated the mailbox databases at the same time we did the upgrade. That would explain it.

• Marked as answer by dpmoody 14 hours 36 minutes ago