You have two options. Both are listed below, with a brief description.
Get the hosted provider to create an account for migration purposes (e.g., named MigrationWiz) and grant full access rights to each mailbox. You will then use this account as the admin account when performing your migration.
Create an account for migration with full access rights to all mailboxes.
- If the Hosted Exchange provider is on Exchange 2007, 2010, 2013, or 2016, ask the provider to create an account for migration (e.g., called MigrationWiz) and then run this PowerShell script against the account called MigrationWiz:
Get-Mailbox -ResultSize Unlimited | Add-MailboxPermission -AccessRights FullAccess -User MigrationWiz
Note: Some Hosted Exchange providers allow this access to be granted via their web portal. In this case, you could log in to each mailbox via their portal and then grant the migration account (e.g., MigrationWiz) to have read/write access to each mailbox. Obviously, this is laborious and time-consuming, and so the preferred method would be for the Hosted Exchange provider to run the above PowerShell script, particularly if you have a large number of users.
Lower the number of concurrent migrations.
From the MigrationWiz user dashboard:
- Click Edit Project.
- Click Advanced Options.
Under the Performance section, change the Maximum concurrent migrations value to a lower number. We recommend beginning with a value of 20. You can always increase this number, and extra items will be added to your migration batch 'on the fly'.
Note: If you decrease the value when migrations have already been submitted, the number of concurrent migrations will not be reduced until the active migrations have completed.
Create a project without admin credentials, and request credentials from users.
- Create a MigrationWiz mailbox migration project. When entering the Source information, do not click the checkbox to enter admin credentials.
- Click the green bar Bulk Add.
- Click the checkbox I don't know the login name and password for the Source mailboxes.
- Click the Upload bar.
- Click the Choose File button, and select and upload your CSV file that contains the list of mailbox names.
- Click Save.
When you submit the mailbox for migration, we will send an email with a secure link in which allows the end user to provide their credentials directly to the system. The sequence of steps are as follows:
- You submit the item for migration.
- An email is sent to the email address configured with a secure link to provide the credentials.
- The end user clicks on the provided link, which opens a secure web page.
- The end user provides their credentials directly to our system.
- The credentials are verified.
- The item is immediately submitted for migration.
The status of the migration will remain as "Waiting For End User" until the end user provides their credentials to the system.