DMA does not migrate Exchange Service Accounts. When migrating users one will have to practice extra care so that you do not migrate the Exchange Service Account.
No, DMA does not migrate the Exchange Service Account. DMA only translates security on the existing mailboxes.
We recommend that customers follow the procedures set forth by Microsoft PSS for migrations involving the Exchange Service Account update.
A separate NetIQ product, Exchange Migrator, will let you perform Exchange inter/intra-org and inter/intra-site migrations with mailboxes, distribution lists, public folders, and custom recipients. You can learn more about it here: https://www.netiq.com/products/Administration/Exchange_Migrator/Default.asp
Please contact Technical Support to create a Support Request for any issues you encounter that are not addressed by the User Guide, any Knowledge Base articles found on the website, or current hotfixes available for download.