Exchange 2007 — Recovering Corrupt Public Folders

After a power outage took down multiple servers, our Exchange 2007 environment came back online — except for the public folder database. The store wouldn't mount, and mailbox users who relied on shared calendars and contacts were dead in the water.

The recovery process:

1. Ran ESEUTIL /P for a hard repair on the public folder database — this fixes page-level corruption but can cause data loss
2. Followed with ESEUTIL /D to defragment and reclaim space
3. Ran ISINTEG -FIX to repair logical corruption at the Information Store level
4. Mounted the repaired database and verified folder hierarchy

Lessons learned:

• UPS is not optional. Every server that hosts data should be on battery backup with graceful shutdown configured
• Circular logging is dangerous — without transaction logs, you can't do point-in-time recovery
• Test your backups. We had backups, but discovering the public store was corrupt before needing it would have been better

Modern context: Exchange Online has largely eliminated this class of problem — Microsoft handles database maintenance and redundancy. But for on-prem Exchange, DAGs (Database Availability Groups) with multiple copies are the minimum standard.