Easily open and view OST files with the Aryson OST Viewer Tool. Load one or multiple OST/PST files, browse mailbox folders, search emails, and preview emails, attachments, calendars, contacts, notes, tasks, headers, MIME content, and raw HTML. Export selected mailbox data to multiple formats, including PST, MBOX, EML, MSG, PDF, CSV, DOCX, ICS, VCF, JSON, and more.
Step 1: Download and launch the Aryson OST Viewer Tool on your system.
Step 2: Add the required OST/PST Files
Load the OST/PST files you want to view, search, preview, export, or migrate.
Add the desired OST/PST file(s), verify the details, and click Proceed to preview and convert the data.
Step 3: Preview & Search OST/PST Mailbox Data
Advanced Preview Panel
The Advanced Preview Panel displays the email's Date, To, From, and Subject fields along with the following mailbox data:
Step 4:Select an Export Format
Once you have reviewed the OST/PST data, select the Export File Format option and choose the required output format. The Aryson OST Viewer Tool supports PST, MBOX, EML, MSG, DOCX, PNG, ICS, VCF, PDF, CSV, MD, JSON, and Mozilla Thunderbird export formats.
Step 5: Apply the Additional Features of the Software
Choose the desired file format or email client and apply the required export settings before starting the conversion.
Note: The File Naming Policy feature is available only for EML, MSG, VCF, ICS, DOCX, PNG, ICS, VCF, PDF.
Use advanced options to customise the export process and manage attachments, duplicates, and file size limits.
Features Exclusive to Specific Formats:
For PST:
Step 6: Click Browse to browse and choose your preferred saving location, and click the Start Export button to begin conversion.
Step 7: Monitor and Complete the OST/PST Migration
After clicking Start Export, monitor the conversion progress and review the processing statistics in real time. The progress window provides details such as the following:
Step 8: Once the export is completed, the Aryson OST Viewer Tool displays the message:
“All selected data has been exported successfully.” You can then use the following options:
Step 4:Mark the Export to Email Clients radio button and select Microsoft 365 as the destination.
Step 5: Authenticate an active Microsoft 365 account
You may choose the A or B login method to log in to the Microsoft 365 account using valid credentials.
Note: While selecting the Office 365 account in the browser window, make sure you have already logged in to the required account before.
Note: Sign in to the required Microsoft 365 account in your browser before starting the migration. If multiple browser windows are open with different accounts, use the one where the required Microsoft ID is already logged in, as authentication will proceed only in that browser.
Enter Azure Application Details
Fill in the following information from your Azure app registration:
| Field | Description |
|---|---|
| Microsoft 365 Admin Account | Admin email address |
| Application (Client) ID | Azure App Client ID |
| Client Secret | Secret generated in Azure |
| Tenant ID | Microsoft Entra ID (Azure AD) Tenant ID |
If you choose Application Credentials Authentication (Client ID, Client Secret, and Tenant ID), you must first create an Azure App Registration and assign the required API permissions in Microsoft Entra ID (Azure AD).
For complete instructions on creating the Azure Active Directory application and enabling API permissions, visit:
Create Azure Active Directory and Enable API Permission GuideIn the guide at step 17, you need to add the required API permissions. The image below lists all the API permissions that must be configured for successful authentication and migration.
B. 1: Choose Mailbox Mapping Mode
B 1.1: Migrate All Files to Selected Mailbox(es):
Select Destination: Microsoft 365 Mailboxes
Note:
Import Users via CSV
B.1.2: Map Each File to Specific Mailbox(es):
Step 6: Return to the Application & Configure Migration Settings & Filters
Step 7: Configure Advanced Migration Filters
Step 8: Click Start Export to begin the OST/PST to Office 365 migration conversion process.
Step 9: Monitor and Complete the OST/PST Migration
After clicking Start Export, monitor the conversion progress and review the processing statistics in real time. The progress window provides details such as the following:
Step 10: Once the export is completed, the Aryson OST Viewer Tool displays the message:
“All selected data has been exported successfully.” You can then use the following options:
Step 4:Mark the Export to Email Clients radio button and select IMAP as the destination.
Step 5: Configure IMAP Server and Authenticate
Step 6: Apply the Additional Features of the Software
Step 7: Click on the Start Export button to begin the OST/PST to IMAP migration.
Step 8: Monitor and Complete the OST/PST Migration
After clicking Start Export, monitor the conversion progress and review the processing statistics in real time. The progress window provides details such as the following:
Step 9: Once the export is completed, the Aryson OST Viewer Tool displays the message:
“All selected data has been exported successfully.” You can then use the following options:
Step 4:Select Google Workspace under the Export to Email Clients drop-down list.
Step 5: Authenticate your Google Workspace account.
Log in via the Workspace admin account and JSON key, and click Authenticate.
You can generate a JSON file with the help of the detailed guide.
Step 6: Map Source Files to Google Workspace User Accounts
Associate the selected source file with the corresponding Google Workspace mailbox before starting the migration.
Step 7: Configure Migration Settings
Step 8: Click on the Start Export button to begin the OST/PST to Google Workspace migration.
Step 9: Monitor and Complete the OST/PST Migration
After clicking Start Export, monitor the conversion progress and review the processing statistics in real time. The progress window provides details such as the following:
Step 10: Once the export is completed, the Aryson OST Viewer Tool displays the message:
“All selected data has been exported successfully.” You can then use the following options:
After downloading the Aryson OLM Converter Tool, you will find the welcome screen as played below.