Before you migrate, you should always check to make sure your credentials are correct among other things to ensure a smooth and pain-free transition.
If you are just migrating a handful of mailboxes, you can manually test each credential of the mailboxes for an IMAP mailbox, Google Apps/Gmail, Exchange 2003, Exchange 2007, Exchange 2010, Office 365, and Life@edu.
Manually testing credentials may be too cumbersome because you are migrating hundreds or thousands of mailboxes. MigrationWiz provides a way to automatically verify your credentials without submitting migrations. This way, you can quickly set up your configuration and see which credentials do not work. We recommend this as a best practices for all migrations by performing it days or even a week before your migration.
In many cases, you will not have access to every end users’ credential. We offer a mechanism in which you can securely request the user name and password through your migration process. When you submit the request, we will send an email with a secure link in which the end user provides their credentials directly to the system. You may choose to request the credentials ahead of time or as you start your migration project.