Open Large PST Files on Windows
MailRelic is a Windows PST viewer for opening and browsing large PST files without importing them into Outlook. It reads the archive directly and leaves the original PST unchanged.
It does not load the whole PST into memory; it reads the parts of the file it needs. It has been tested with a PST file over 10 GB.
What happens when you open a large archive
- The folder tree is shown first, and folders can be opened straight away.
- The search index is built in the background. The status bar shows its progress, and search covers the whole archive once indexing is complete.
- The archive summary shows the attachment count as it is counted, then the final number.
How long indexing takes depends on the computer and on the archive.
Exporting a large archive
With MailRelic Personal, a whole-archive export runs as a job with a progress indicator. It can be cancelled, and MailRelic stays usable while it runs. When it finishes, MailRelic shows a summary and writes a report of what was exported.
On archives with a very large number of items, the export can stay on Preparing for some time before the first message is written.
How large archives were tested
The largest archive used in testing is a 10.7 GB PST containing one million messages in 50 folders. MailRelic's export engine exported all one million messages, and the count matched the contents of the file. In the Windows application, an export of the same archive was used to check that progress is shown and that the export can be cancelled.
This archive was created for testing with a separate PST-writing tool, not by Outlook. It shows that MailRelic handles a file of this size and number of items. It does not prove that every large PST opens, or that every feature a large archive created by Outlook can contain is covered. The PST files created by Outlook that were used in testing are much smaller. Details are on the testing page.