If you’ve ever opened Outlook only to find a blank inbox or an error saying your PST file can’t be opened, you know how frustrating it can be. I’ve been in the same situation, so I decided to find out what actually works. After researching the common causes of PST corruption and testing Stellar Repair for Outlook, I put together this review to share my experience and help you decide if it’s the right solution.

PST files corrupt for a handful of predictable reasons. The most common one is size – older PST formats start acting up once a file grows too large, and even newer Unicode PST files aren’t immune once they balloon past a few gigabytes. Sudden Outlook crashes, or an unexpected system shutdown while the file is being written, can also leave the data file in a broken state. Add malware, a failing hard drive, or a rough network interruption during sync, and you have a recipe for a mailbox that simply won’t open.

Whatever the cause, the result is the same frustrating experience: Outlook refuses to load your folders, emails go missing, and attachments, contacts, and calendar entries you relied on suddenly seem gone. That’s the gap a dedicated PST repair tool is meant to fill, and it’s why I decided to test Stellar’s two options: the browser-based online PST repair service and the full desktop software side by side.