Hello,
This issue could occur if not all Stores in a Storage Group were selected for backup when performing a Full or Incremental backup job in Backup Exec
If one or more Mailbox or Public folder stores are backed up from within a storage group but not all stores in that group are selected, then the logs for that group are not going to be flushed on either a Full or Incremental backup job.
Logs: With Exchange 2000 and 2003, the transaction logs function at the storage group level. This means that all of the databases within a storage group share a common set of transaction logs. Therefore, unless you back up all the databases, transaction logs will not be deleted.
For more information, see Microsoft Article: Q182961 "Using Eseutil to Determine Which Logs Have Been Committed."
Thanks,
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