How can I avoid duplicate emails when backing up or migrating Office 365 mailboxes?

You can avoid duplicate emails during Office 365 backup or migration by using a tool with built-in duplicate detection and skip options. The SysInfo Office 365 Backup Tool provides features designed to prevent repeated mailbox items during backup and migration.
Before starting the process, select the required mailboxes and folders, then enable the Remove Duplicate option. The software can identify duplicate emails and other mailbox items based on selected criteria. You can also use the Skip Previously Migrated option when running repeated migration or backup tasks, helping prevent the same data from being processed again.
For better control, apply date filters to select only the required emails and preserve the original folder structure during export. You can also choose specific folders instead of processing the entire mailbox. These options help reduce unnecessary copies, save storage space, and keep the destination mailbox or backup file organized while maintaining important email data and attachments.