Stellar Converter for OST in test

When Outlook Crashes—This Tool Saves Your Emails

What is it all about?

Outlook is a daily companion at work for many people. As long as everything is running smoothly, you don't notice the so-called OST files in the background—they dutifully provide offline access and synchronization. But heaven forbid the Exchange connection drops, the profile gets corrupted, or Outlook acts up. Then you're stuck with a pile of data you can no longer open.

This is exactly where Stellar Converter for OST comes in. The tool promises to convert such corrupted or unsynchronizable OST files into the universal PST format—including emails, attachments, contacts, calendars, and more.

We tested the tool in the Corporate Edition on a Windows 11 system with an OST file of just under 3 GB – here is our review.

Installation & interface

Installation is quick and easy: Download, run the setup, wait a few seconds—and you're done. No restart, no annoying extra tools. Once launched, the interface looks pleasantly uncluttered. Anyone who's ever used Outlook will feel right at home.

When the tool starts, it automatically searches for existing OST profiles. Alternatively, you can load files manually.

The conversion process - here's how it works

After loading the file, the scanning process starts. With our 2.95 GB file, this took a mere 3.5 minutes – quite respectable. The tool also remained stable during conversion, with no freezing or hanging.

The progress bar looks a bit outdated—but the scan is fast and reliable.

After the scan, you can browse directly through the entire structure – including folders, calendar, notes, and attachments.

The preview feature is worth its weight in gold—it lets you search specifically for lost data or export only certain folders.

Afterwards, the file can be exported in various formats: PST, MSG, EML, RTF, HTML, or PDF. Anyone who wants to continue using Outlook can stick with the classic PST format.

Handy: The export formats cover a wide range of scenarios—including archiving and legal purposes.

Operation & features

The user guidance is self-explanatory: select OST file, scan, browse data, export. No technical jargon, no pitfalls. Anyone who wants to can also export only specific folders, date ranges, or senders. Deleted emails can also be displayed and recovered.

Plus point: The tool also supports large files (3+ GB) without batting an eye. During export, there is the option to automatically split huge PST files—important for Outlook, which often acts up with PSTs that are too large.

Performance & stability

On our test system (16 GB RAM, SSD, Outlook 64-bit), the Stellar Converter ran smoothly throughout. The conversion itself took under 4 minutes, and exporting the 3.81 GB PST file took another good 4.5 minutes—so a total of under 9 minutes for a complete rescue operation.

Overall, the process ran without errors, the tool responded quickly and generated a clean file without data loss.

Accuracy & data integrity

The most important question: How much of the OST file actually transfers over? The answer: Pretty much everything. All folders were transferred correctly, the email structure remained intact, attachments, contacts, calendar—everything is there. There was a display error with one PDF attachment; otherwise, the conversion was error-free.

A real plus for business users and admins: the folder structure is completely retained even with more complex Exchange structures.

Compatibility

The converter ran for us under Windows 11, but also recognizes older Outlook installations without any issues. The manufacturer lists support up to Outlook 2007. Office 365 profiles and IMAP accounts are also recognized—so the tool is not just interesting for classic Exchange users.

Functions & differences between editions

In addition to pure conversion, Stellar scores points with a few nice extras:

• Restore Deleted Items
• Filter functions for targeted export
• Multiple file formats
• Save Scan & Continue Later
• Split Function for Large PST Files

Anyone who wants even more needs the Technician or Toolkit Edition. These offer direct export to Office 365 or batch conversion, for example. However, the Corporate version is completely sufficient for the classic single user.

Security & trust

The tool ran smoothly for us—no unwanted processes, no dubious network traffic, no system interference. The manufacturer's privacy policies are transparent, there is no cloud connection—the entire tool runs locally.

Stellar itself is an old hand in the data recovery sector and enjoys a good reputation. You can also tell this from the uncluttered software and regular updates.

Price-performance

The Corporate version currently costs around 79 euros—not exactly a bargain, but fairly priced given its features, speed, and reliability. A free trial version at least allows you to preview files, but you can’t export them until you’ve purchased the software.

Anyone who regularly struggles with Outlook backups, broken profiles, or Exchange issues will appreciate the tool. For single-use users, a lifetime model without a subscription would be desirable.

Conclusion

Simple, fast, reliable—that's what a recovery tool for Outlook data needs to be.

The Stellar Converter for OST impressed us during our testing: fast conversion, a well-designed interface, and error-free data transfer. The preview feature before exporting is particularly handy—it allows you to selectively save specific emails or folders.

Criticism? Minor details. The UI could be more modern, and a lifetime model for private users is missing. But at the end of the day, Stellar delivers a tool here that does exactly what it's supposed to do – and pretty well.