If your database is corrupted heavily, it is likely jet errors will occur. In most cases, Jet errors are not repairable. The most common error our customers usually see is: JET_errRecordNotFound, which is never recoverable using the eseutil.exe program. In fact, in many cases where this error appears, running eseutil will result in additional lost time and data. Another problem are 1003 0xFFFFFC15 JET_errInvalidParameter Invalid API parameter 4294966293 error codes.
The “JET_errKeyDuplicate Illegal duplicate key”, is another jet error message that occurs due to database corruption. Running eseutil typically does not restore your Exchange Server functionality.
An important error is ESE97 Error Codes:
JET_errReadVerifyFailure Read verification error 4294966278. Typically this can be due to hard drive sector errors. It can also be that some information may have been written incorrectly into the database file, typically caused by Exchange Recovery Software Utilities. Another problem is the database file is corrupt or the Exchange Server Jet Engine is corrupt.
Although Restoring Exchange Server information stores with eseutil can fix a crashed Exchange Server, it can also corrupt it. The eseutil utility will change values in the Exchange Server data file. We highly recommend you do not perform this utility unless you have saved all the log files, the .EDB or STM files before. This is not a utility to be taken lightly or try it to see if you can get it to work.
RMD recovers Exchange Server databases that have failed or crashed.
Our findings indicate that Exchange Server typically crash due to:
Physical hard drive failure.
Controller card failure.
File size errors.
Drive sector errors.
Virus attack on exchange server.
Exchange program failure.
Partition table corruption.
We highly recommend you contact us before you attempt an Exchange Server Recovery or use an Exchange Server Software utility.