Mailbox Migration - full guide

Browse to the migration platform and login with your username and password

On the left hand side, click on New  Migration

Type in the name for your migration into Batch name field and select email from the tile selection

Select HEX 2010+ as the source Source  and Office 365 as the Destination platform from the platform tile selection.
Enter the admin credentials for both of them. Make sure that entered user has impersonation rights set on those servers.
Click on Next in the upper right corner

Choose if you would like to use Autodiscovery or Upload CSV method from "Choose type of email discovery" window

If Autodiscovery method is used, list of available mailboxes on the source will be shown. Select some or all of them (depending which ones you want to migrate) and click on Next in the upper right corner.

Recommended: read about licensing before you continue

Optional: Click on Analyze if you wish to check the aproximate mailbox size before you proceed to the next step

If Upload CSV method is used, EWS Location must be provided, PoweShell Location is optional
Click on CSV button and browse to your CSV file and after you add it click on Discover

If your agree for analysis to run slower, click OK on "Without PowerShell address provided, mailbox analysis can still be done, but it will run slower" window.
If you don't agree with this, click on Cancel and supply the PowerShell URL

If the CSV is in the proper format, it will take you to the next step.
List of the available mailboxes on the source will be shown. Select some or all of them (depending which ones you want to migrate) and click on Next in the upper right corner.

Recommended: read about licensing before you continue

Optional : Click on Analyze if you wish to check the approximate mailbox size before you proceed to the next step

Wizard will take you to Mailbox Mapping tab of the Settings page.
If some mailboxes which exist on the source don't exist on the destination, their fields will be empty. Read more about how to resolve this here

On General Settings tab, select the data center which is the closest to the source server or if you want to migrate only specific item types, select the ones that you need
If some or all mailboxes will consume more than one license  you can automate the license consummation process by selecting the Automatically consume more licenses if needed checkbox.

On Migration Scheduler tab you can specify if you want this migration job to run now or specific time when each selected mailbox will be migrated.

On Notifications tab specify email address and phone number for each type of the notification. All of these are optional.

When everything is configured, click on Start Migration in the upper right corner.

If there are no errors in the configuration, Dashboard will be shown with the list of all migration jobs and their statuses

Basic Details about the selected migration job will be shown in the upper right corner.

For more detailed report, click on Full Details

Status column will show which mailboxes were migrated successfully and which ones were not.

For more details about the mailboxes which failed to migrate, click on cogwheel on the right side.

After the migration is done Resync and Remigrate options will be available.