I cannot do it no matter what I do
If Outlook’s built-in import isn’t working, you’re not alone. Manual PST imports to Microsoft 365 can fail because of large mailbox sizes, profile issues, or sync problems. I had a similar issue and used Softaken PST to Office 365 Importer, which made the migration much easier. It imports PST and OST files directly to Microsoft 365 using secure OAuth authentication without requiring Outlook or an Exchange server. It also preserves folder hierarchy, emails, contacts, calendars, tasks, and attachments, supports pause/resume, avoids duplicate imports, and generates an HTML migration report. If you have a large PST file, this approach is much more reliable than the manual method.
Key points:
- No Outlook installation required
- Secure Microsoft Graph API with OAuth
- Preserves folder structure and all mailbox items
- Supports PST, OST, Office 365, and IMAP
- Duplicate protection and resume support
- Free trial available
If you want to import PST files to Office 365 quickly and securely, you can try MailsDaddy PST to Office 365 Migration Tool. It allows you to import single or multiple PST files directly to Office 365 mailboxes while preserving folder hierarchy, email properties, attachments, and other mailbox items. The software supports bulk migration, selective data transfer using filters, and secure authentication. It smoothly works with all Outlook PST file versions, making it an ideal solution for both individuals and organizations.
Read: Step by step guide - Migrate PST to Office 365
If you want to import an Outlook PST file into Office 365, Microsoft provides native import options, but they can be time-consuming because they often require network uploads, Azure storage, or Outlook configuration. For small migrations, those methods work, but they may not be the most convenient for every user.
If your goal is a faster and more straightforward migration, a PST to Microsoft 365 migration tool can simplify the process. I recently assisted with moving several archived Outlook mailboxes, and WholeClear PST to Office 365 Converter made the migration much easier. After selecting the PST file and signing in to the Microsoft 365 account, the software imported emails, contacts, calendars, tasks, and attachments while preserving the original folder hierarchy and email properties. It also provided a preview before the migration and didn’t require Microsoft Outlook to be installed on the computer.
Before starting, it’s a good idea to create a backup of your PST file. Once the import is complete, verify that your folders and mailbox items appear correctly in your Office 365 account before removing the local archive.