A corrupted OLM file can often be recovered, depending on the damage. First, make a backup copy so the original stays untouched. If the original mailbox is still available, rebuild the Outlook database using Database Utility, or re-export the data in smaller batches, since one damaged item can break a full export. If the mail lives on Exchange, Microsoft 365 or IMAP, simply sync it again from the server. When the OLM file is your only copy, a tool like Kernel OLM to PST Converter can read the damaged file, show what’s recoverable in a preview, and save it as PST. Always spot-check the recovered folders afterward.