You may notice after you have migrated an Exchange 20032007 On-Premise user to O365 Exchange Online that the Archive Feature is not avalible. to enable the feature please run though the following steps
To enable the migrated users to have an Archive Mailbox please run though the following
Once the user’s mailbox has been migrated to O365 Exchange Online logon to the Exchange 2010 Coexistence Server
Launch Powershell for Exchange 2010
Then run the following
Get-MailUser –Identity “User name” | Enable-RemoteMailbox
Wait for Directory Sync to occur or execute manually by running the following Powershell on the DirSync Server using the Powershell Modules Prompt:
‘Start-OnlineCoexistenceSync’
Once the Sync has completed Logon to the Exchange 2010 Coexistence Server
Under your On-Premise organisation.
Expand Recipent Configuration
Expand Mail Contact
Right click the Mail User Contact (should now have the Recipient type of ‘Remote User Mailbox’
Select ‘Enable Hosted Archive’
Wait 30mins and the Online Archive will appear in the O365 Users OWA or Outlook
Alternative to EMC you can use EMS
Enable-RemoteMailbox, parameters {Archive=True, Identity=domain.com/Users/Luke Smith}