#Pre-analyze Mappings (Optional)

After creating mappings for Exchange Online migrations, you can scan data of the source mailboxes before running the migration to overall understand the data counts and can also verify whether the mappings are ready for migrations.

Refer to the following steps to pre-analyze mappings:

1. Click Projects in the left pane to access the Projects page, and click the project name of the project for which you want to pre-analyze mappings.

2. On the Project mappings page, select one or multiple mappings you want to pre-analyze.

3. Click Pre-migration, and select one of the following actions for the mappings.

   • Verify mapping – This action will analyze whether the mailbox/distribution list/dynamic distribution list in the mapping is available for the migration. If the shared mailbox in the destination does not exist, Fly can create a new one. If the distribution list/dynamic distribution list/mail-enabled security group/Microsoft 365 Group to which you want to migrate the distribution list/dynamic distribution list/mail-enabled security group does not exist, Fly can also create a new one in the destination.

   • Scan source data – This action will scan and analyze the sizes and objects of source mailboxes. When the scan is completed, the Source data scan report will be generated for the mappings to allow you to understand the mailbox size and the object counts of the source mailbox. You can click the source email address of each mapping to view the report.

   • 

     After the Scan source data job of mappings starts, if you want to stop the job, you can select the mappings and click Stop, then the Scan source data job of the selected mappings will be stopped. If you run another job for the stopped mappings, the job will start from the beginning.

When the mappings within the project are ready for migrations, you can run migrations for the mappings to migrate objects.