Download, install, and launch the SysInfo OST Viewer Tool on your Windows system.

Click Load Outlook Files to automatically load OST files associated with configured Outlook profiles, or select Choose Manually to browse and add an OST file from your local system.

Click Browse and navigate to the location where the OST file is stored on your system. Select the desired file and click Open to load it into the software.

After loading the OST file, the software allows you to preview complete mailbox data, including emails, attachments, tasks, notes, message headers, MIME content, and raw HTML information. This detailed preview helps you analyze mailbox items before proceeding with any further action.

Select the desired email from the preview panel and click Open in Browser in the bottom-right corner. The software will open the complete email content in your default web browser for a detailed and convenient view.

After reviewing the mailbox contents, click Save Outlook File to proceed with saving the OST mailbox data. This option allows you to export and store the Outlook file at the desired location for future access and use.

Select the desired file format for saving the OST mailbox data. The software provides multiple saving options, including PST, EML, MSG, PDF, MBOX, and CSV, allowing you to export mailbox items according to your requirements.

Select PDF as the output format to save Outlook emails as PDF documents while preserving email formatting, metadata, and attachments. This format is useful for document sharing, printing, archiving, and compliance purposes.

Use the Duplicate Handling feature to identify and manage duplicate mailbox items during the saving process. This option helps prevent redundant data storage, reduces clutter, and ensures a cleaner and more organized output after exporting the OST mailbox data.

The Attachment Handling section provides multiple options for managing email attachments during the export process. Select the appropriate option based on your requirements for storing and organizing attachment data.

• Keep Attachments: Preserves all original attachments within the exported email files.
• Attachments as Pages: Saves email attachments as separate pages within the output document for easier viewing and reference.
• Extract Attachments Separately: Extracts all attachments into a dedicated folder while saving the corresponding emails independently.
• Exclude Attachments: Omits all attachments during export, saving only the email content and reducing the overall output file size.

Use the Custom Folder option to define a preferred folder name for saving the exported mailbox data. This feature helps organize output files efficiently and makes it easier to manage exported data.

Use the Date Filter option to export mailbox items from a specific time period. This feature helps perform selective exports and ensures that only the required emails are included in the output.

• All Dates: Exports all mailbox items without applying any date restrictions.
• Include Selected Date: Exports only those emails that fall within the specified start and end dates.
• Exclude Selected Dates: Excludes emails that fall within the selected date range while exporting all remaining mailbox items.
• Start Date: Specify the beginning date for the mailbox filtering process.
• End Date: Specify the ending date to complete the selected date range for export.

The Skip Existing / Resume Export feature allows users to continue interrupted export operations without restarting the entire process. It automatically detects previously exported data, skips completed items, and resumes the remaining export tasks efficiently.

• Enable Skip/Resume Detection: Automatically identifies completed export files and resumes unfinished export operations while preventing duplicate data creation.
• Not Complete Files: Displays mailbox items or files that were only partially exported and still require processing.
• Target Path: Shows the source location of the files selected for the resume export process.
• Output Folder: Displays the destination folder where resumed and newly exported files will be saved.

Use the Browse option to navigate through local drives and select the desired destination folder for saving the exported mailbox data. Choosing the appropriate destination path ensures that exported files are stored securely and can be accessed easily after the export process is completed.

After configuring all required export settings, click Save to begin the mailbox saving process. The software exports the selected mailbox data according to the chosen file format, filters, attachment preferences, and destination path settings.

Once the saving process is finished, the software displays a confirmation message indicating that the OST mailbox data has been successfully exported.

Download, install, and launch the SysInfo OST Viewer Tool on your Windows system.

Click Load Outlook Files to automatically load OST files associated with configured Outlook profiles, or select Choose Manually to browse and add an OST file from your local system.

Click Browse and navigate to the location where the OST file is stored on your system. Select the desired file and click Open to load it into the software.

After loading the OST file, the software allows you to preview complete mailbox data, including emails, attachments, tasks, notes, message headers, MIME content, and raw HTML information. This detailed preview helps you analyze mailbox items before proceeding with any further action.

Select the desired email from the preview panel and click Open in Browser in the bottom-right corner. The software will open the complete email content in your default web browser for a detailed and convenient view.

After reviewing the mailbox contents, click Save Outlook File to proceed with saving the OST mailbox data. This option allows you to export and store the Outlook file at the desired location for future access and use.

Choose the Select the desired file format for saving the OST mailbox data. The software provides multiple saving options, including PST, EML, MSG, PDF, MBOX, and CSV, allowing you to export mailbox items according to your requirements.

Choose PST as the output format to save Outlook mailbox data in a widely supported email file format. The software preserves email formatting, folder hierarchy, metadata, and attachments during the conversion process.

Use the Duplicate Handling feature to identify and manage duplicate mailbox items during the saving process. This option helps prevent redundant data storage, reduces clutter, and ensures a cleaner and more organized output after exporting the OST mailbox data.

The Attachment Handling section provides multiple options for managing email attachments during the export process. Select the appropriate option based on your requirements for storing and organizing attachment data.

• Keep Attachments: Preserves all original attachments within the exported email files.
• Attachments as Pages: Saves email attachments as separate pages within the output document for easier viewing and reference.
• Extract Attachments Separately: Extracts all attachments into a dedicated folder while saving the corresponding emails independently.
• Exclude Attachments: Omits all attachments during export, saving only the email content and reducing the overall output file size.

Use the Custom Folder option to define a preferred folder name for saving the exported mailbox data. This feature helps organize output files efficiently and makes it easier to manage exported data.

Use the Date Filter option to export mailbox items from a specific time period. This feature helps perform selective exports and ensures that only the required emails are included in the output.

• All Dates: Exports all mailbox items without applying any date restrictions.
• Include Selected Date: Exports only those emails that fall within the specified start and end dates.
• Exclude Selected Dates: Excludes emails that fall within the selected date range while exporting all remaining mailbox items.
• Start Date: Specify the beginning date for the mailbox filtering process.
• End Date: Specify the ending date to complete the selected date range for export.

The Split PST File feature helps users divide large PST files into smaller, manageable parts during the saving process. This option improves file management, simplifies sharing, and helps maintain optimal Outlook performance.

• Enable Splitting: Activate this option to automatically split the resulting PST file into multiple smaller PST files during export.
• Split Into: Specify the maximum size limit for each split PST file in MB or GB based on your storage and management requirements.
• Store Name: Assign a custom name to the split PST file set for easier identification and organization after the export process is completed.

The Text Filters section enables users to export only the required mailbox data by applying specific filtering conditions. These filters help narrow down email selection based on sender, recipient, or subject information before starting the export process.

• To: Filter emails based on recipient email addresses. Users can include or exclude specific recipients to export only relevant mailbox items.
• From: Filter emails from specific senders or domains to export communications from selected contacts.
• Subject: Search and export emails containing particular subject keywords or phrases for targeted mailbox extraction.

These filtering options help minimize unnecessary data export, reduce processing time, and improve overall mailbox management efficiency.

The Skip Existing / Resume Export feature allows users to continue interrupted export operations without restarting the entire process. It automatically detects previously exported data, skips completed items, and resumes the remaining export tasks efficiently.

• Enable Skip/Resume Detection: Automatically identifies completed export files and resumes unfinished export operations while preventing duplicate data creation.
• Not Complete Files: Displays mailbox items or files that were only partially exported and still require processing.
• Target Path: Shows the source location of the files selected for the resume export process
• Output Folder: Displays the destination folder where resumed and newly exported files will be saved.

Use the Browse option to navigate through local drives and select the desired destination folder for saving the exported mailbox data. Choosing the appropriate destination path ensures that exported files are stored securely and can be accessed easily after the export process is completed.

After configuring all required export settings, click Save to begin the mailbox saving process. The software exports the selected mailbox data according to the chosen file format, filters, attachment preferences, and destination path settings

Once the saving process is finished, the software displays a confirmation message indicating that the OST mailbox data has been successfully exported.

Download, install, and launch the SysInfo OST File Viewer Tool on your Windows system.

Tap Add Outlook File >> Load Outlook Files to automatically load OST files associated with configured Outlook profiles, or select Choose Manually to browse and add an OST file from your local system.

In Outlook Data Files, tap on Mailbox Path, and it will automatically fetch the PST/OST files on your system with their status displayed. Click Load to upload them.

Alternatively, under Choose Manually, tap Browse and navigate to the location where the OST/PST file is stored on your system. Select the desired file and click Open >> Load to upload it into the software.

After loading the OST file, preview complete mailbox data, including emails, attachments, tasks, notes, message headers, MIME content, and raw HTML information. This detailed preview helps you analyze mailbox items before proceeding with any further action.

You can use the Email List Search bar to locate specific emails based on a particular keyword or apply Smart Search filters based on To, From, Subject, Date Range, and Has Attachments.

Select the desired email from the preview panel and click Open in Browser from the Body tab in the bottom-right corner. The software will open the complete email content in your default web browser for a detailed and convenient view.

Tap Migrate to Office 365, and it will open a dialog with different authentication modes. Here, Modern Auth 2.0 is divided into two more modes for secure authentication via the Graph API. Another is using Admin Impersonation via Client ID, Client Secret, and Tenant ID.

1. Modern Authentication : As mentioned, it is divided into two auth types. First, we will go with Single User login. Enter your Outlook email ID to proceed. You will be redirected to the browser for secure authentication via password login and Microsoft permissions acceptance.
   
   Another is using the Admin ID; here, also input your Microsoft 365 Admin ID and click Remember this Account to save the account for future use. You can do it in any mode of the Office 365 login. Click Authenticate, and it will try to connect. Ensure you have proper internet for this task.
   
2. Client Secret : Here, you need to provide your Client and Tenant IDs with the Client Secret Key and press Authenticate for direct login to the Office 365 account.

Before you perform the final authentication of your account, opt for the migration scope, folder strategy, and filter as specified below:

• Scope: Choose what you want to transfer from your OST files (Emails, Contacts, or Calendar Events).
• Remove Duplicates: Use it to skip similar items based on To, From, Subject, Date, CC, and BCC.
• Follow Tree Hierarchy: This allows you to save the OST emails in your Office 365 account in the same structure as in the Outlook OST file you uploaded.
• Mapped with Default Mailboxes: It lets you save your OST mailbox data in specific Office 365 mailbox folders by default, like (Inbox, Sent, Drafts, etc.)
• Export to Custom Folder: You can assign a custom name for your Office 365 resultant mailbox data. If none is assigned, it is generally saved in automatic date format.
• Date Filter: Enable it to opt for a From and To date to move emails and folders specifically for that period only.

Once you have configured your Office 365 account, a confirmation message will appear. Click Proceed to continue the migration.

Before proceeding, you will be asked to finally choose which PST/OST folders you want to migrate. Select and tap Confirm Selection to continue.

In the next dialog, you will be asked to select the destination Office 365 account to map the PST folders where you want to transfer. Select the specific IDs and click Apply to map them (1-1, 1-M, M-1, M-M).

If you have some specific accounts that you want to map your PST folders to, click CSV Import to add a CSV containing the Office 365 accounts' email addresses for mapping.

Finalize the mapping and click the Save Mapping & Start button to initiate the OST to Office 365 migration with this smart viewer tool. You can select specific mapped folders to proceed with from the Migrate section.

You will see the migration in progress in real-time status. You can check emails skipped, migrated, failed, and other details. Use the Stop button to halt the process in between if required. Once completed, a migration completed dialog box appears; click OK.

Once everything is finished, click the Log Reports button from the top to check the status. Click Open Folder to see a detailed report, and OK to close.