Introduction Migrating mailboxes from one Exchange environment to another, whether upgrading from Exchange 2010/2013/2016 to Exchange 2019 or moving to Office 365/Microsoft 365 is a complex process that can bring significant improvements in performance, reliability, and security. However, migration is not without its challenges. One of the most critical and common post-migration issues is mailbox access problems. Users may experience: Inability to open Outlook or access mailboxes Repeated log...
