How do I migrate OST data from Outlook 2016 to Outlook 365?

Migrating OST data from Outlook 2016 to Outlook 365 generally involves exporting mailbox content from the OST file into PST format and then importing the PST into the new Outlook 365 profile. This process is particularly useful when the OST file is orphaned, inaccessible, or disconnected from its original Exchange account.

A tool like SysInfo OST Converter Tool can simplify the migration by extracting all mailbox components from the OST file, including:

• Emails and attachments
• Contacts
• Calendars
• Tasks
• Notes
• Journals

The software also supports bulk OST conversion, date-range filtering, duplicate removal, and splitting large PST files if necessary. These features become especially useful when dealing with large corporate mailboxes.

The migration process usually follows these steps:

1. Add the Outlook 2016 OST file.
2. Preview mailbox items.
3. Select PST as the output format.
4. Convert the OST file.
5. Create or configure the Outlook 365 profile.
6. Import the PST using Outlook's Import and Export Wizard.

This method helps preserve folder hierarchy, metadata, email formatting, and attachments, ensuring a smooth transition from Outlook 2016 to Outlook 365.