During the last week of your migration, there will be an administrative lockdown period called Maintenance Mode which affects the Admin Center only and does not affect users accessing your archive
data. Your company transition contact will be notifed 10 days before. Maintenance-Mode places the EHA into a read-only state and no further changes can be made to the configuration of EHA. This includes:
Maintenance-Mode does not affect the EHA Viewer and users can continue to logon to perform searches, exports, reviews and any other Viewer tasks as they would normally be able to perform.
Maintenance-Mode ends at Migration-Complete. Migration-Complete is the point at which all users begin using Office 365 and stop using EHA. After Migration-Complete you can still logon to the EHA
service for approximately 15 days, but all Admin, Viewer and Reports activity is now read-only. All new messages are ingesting in to Office 365 and all activity by administrators and users is now done in Office 365.
Microsoft will export and send a copy of all EHA messages to you on encrypted portable media via overnight courier. Once this has been delivered, your EHA data will be deleted from the EHA system
and your EHA account will be taken out of service permanently.