What are the most common user complaints after Exchange to Office 365 migration?

[arjunmehta]

After migrating from on-premises Exchange to Office 365, users commonly report several issues. The most frequent complaint is temporary email disruption, including missing or delayed messages during synchronization. Login and authentication problems also arise, especially with multi-factor authentication or outdated credentials. Users often notice changes in interface and features, leading to confusion and productivity dips. Another concern is incomplete data migration, such as missing folders, contacts, or calendar entries. Performance issues like slow Outlook response or syncing delays are also common. Permission and access errors in shared mailboxes or calendars can frustrate teams. Additionally, users may face problems with mobile device configuration and re-syncing. Storage limits and unexpected mailbox quotas can also trigger complaints. Finally, lack of proper training and communication during migration often amplifies these issues, making the transition feel more disruptive than necessary. Better planning reduces migration risks.