We’re helping an organization who wanted to start using Office 365 for their email immediately, without migrating items. We initially set up DirSync and used it to create the accounts. But the users still had on-prem mailboxes. This prevented the new Office 365 user from having a mailbox provisioned. The organization didn't want to migrate mail, otherwise an Staged Exchange Cutover would have provisioned the O365 mailbox.
We turned off DirSync and deleted the synced accounts from O365. Then created the users manually using Bulk Import in Office 365. The users are now connected to their O365 mailboxes using their cloud identity.
We will decommission on-prem Exchange, hopefully removing the Exchange attributes from the on-prem account. Then we plan to turn DirSync back on.
- At this point, will DirSync soft match the on-prem account with the O365 account? The primary SMTP address is the same between on-prem and O365.
- Is there a way to get DirSync syncing now, while the on-prem Exchange server is running, to control the O365 accounts from on-prem AD? Would that involve deselecting a list of Exchange attributes in the Active Directory Connector Management Agent, in the Synchronization Service Manager? If so, what attributes should I deselect?
Any direction or links to resources would be greatly appreciated.