Perform the following steps to run a Delta pass on a migration from PST files:
1. Export the PST files using the default option (in Outlook, this is Replace duplicates with items exported) on the last step, where you give the PST file a name.
2. Refer to our KB article on uploading PST files to upload the PST files.
3. Follow our PST migration guide to migrate the PST files. Note: Do not delete the Azure blob yet, as you will need it for the steps below.
4. Go back into Outlook and export the PST files again. This time, use the Do not export duplicates bubble on the last step, where you name the PST file.
5. Upload the new PST files using the -force true parameter at the end of your UploaderWiz command, to force the previous files with the same name to be replaced.
6. Run another Full Migration.
7. Follow the Post-Migration Step in the PST Migration Guide.