Yahoo Mail supports IMAP, so you can move its email data to Microsoft 365 without first creating PST files. Microsoft’s own migration process requires the destination mailboxes to exist before the transfer and only migrates mail folders, not contacts or calendars.

A Simple Way to Move Yahoo Mail to Office 365

Create and license the required Microsoft 365 mailboxes. Confirm the Yahoo account can be accessed through IMAP and prepare the required credentials. Connect the Yahoo mailbox as the source and Microsoft 365 as the destination. Select the required folders and start the migration. Verify the migrated messages before changing your mail routing or MX records.

For a more controlled Yahoo to Office 365 transfer, Softaken IMAP to Office 365 Migration can be considered because it works directly between the mailboxes without a PST and supports folder mapping, date/folder filters and incremental synchronization. It also provides HTML/CSV migration reports for checking completed or failed items.

A small pilot mailbox is worth testing first, especially before moving a larger set of Yahoo accounts.