Make sure that all associated accounts are matched or migrated and create the Mail Migration task:
- Open Mailboxes and select the mailboxes you want to migrate.
- Click Migrate Mailboxes.
- Select the active licensing plan with Exchange Online options that will be used on the target tenant. Re-run the discovery task to update available licensing plan data, if necessary.
- Specify how the licenses will be assigned to the target users during the mailbox provisioning:
- Replace all license assignments with the licenses from the selected plan. Licensed users will be switched to the selected plan.
- Retain the existing licenses and assign the selected plan only to unlicensed accounts (default). Licensed users will retain the existing plans.
IMPORTANT: Consider the following:
- Resource mailboxes that have not been licensed on the source tenant will retain the unlicensed status.
- Licensed resource mailboxes will be handled according to the selected option.
- In case no usage location is set on the target the source value will be used for the assigned license. Otherwise the target usage location value remain unchanged and can be modified manually, if necessary.
Selected licensing option is only applicable to Exchange Online. It does not affect the licensing plans picked for OneDrive Migration. Click Next.
- Specify the migration scenario.
- From Primary Mailbox to Primary mailbox - migrate content of the primary mailbox (default scenario.)
- From Archive mailbox to Archive mailbox - migrate content of the archive mailbox.
- From Archive mailbox to Primary mailbox - restore archived content to primary mailbox.
- From Primary mailbox to Archive mailbox - migrate some of the content of the primary mailbox to archive. Useful with the specific Migration Options selected.
Tip: It can take a while to migrate mail to archive mailboxes. Source mailboxes that have archives can be easily selected using Inventoryreport on Assessment view of Mailboxes. It would be useful to re-run the Discovery task to update the information.
- Specify which mailbox items (email, contacts, calendar appointments, recoverable items, tasks, and so on.) you want to transfer to the target.
Caution: Recoverable items, mailbox delegation, and folder permissions are not included by default, thus they are not transferred to the target. If you want to keep this data select corresponding option on this step.
Consider the following:
- Mailbox delegation permissions (Full Access, Send As, and Send On Behalf) can be transferred only in case the matched delegate exists on target. In case matched delegate does not exists, mailbox delegation cannot be migrated and an error will be reported. In case the target mailbox delegation is not set, the mailbox delegation will be transferred as is. In case the mailbox delegation as been set in target before the migration starts, rules and exceptions specified in Migrating Delegate Access Permissions section of On Demand Migration for Email User Guide are applicable to set mailbox delegation.
- Folder permission in case the target permission does not exist will be transferred as is. In case the folder permissions were already set in target before the migration starts, rules and exceptions specified in Migrating Folder Permissions section of On Demand Migration for Email User Guide are applicable to set folder permissions.
NOTE: Migration of folder permissions for Recoverable Items is not supported.
- Specify which mail folders should be transferred during mail migration processing, if necessary. Click Next.
- Limit the date range for content transfer. You can set any of the following options:
- Migrate mail before to set end date for the date range
- Migrate mail after to set start date for the date range
- Schedule when the task will be started. See Task Scheduling for details.
- Click Next to view the task summary. Name the task and check selected options. Click Finish to save or start the task depending on schedule option selected.
The mail migration task is created. You can track its progress in the Tasks, view the summary on the Dashboard or monitor alerts and notifications in the Events.
Mailbox Migration Considerations
- The following types of mailboxes are supported: Regular, Room, Equipment (Resource), Shared.
- During the mail migration, users might receive email to both source and target mailboxes. Apparently the users might want to receive the email sent to both mailboxes. To achieve this, we automatically set up mail forwarding from target to source which works until the clients are switched to the target tenant.
The mail migration is complete and you have deployed Client Update Agent in your on premises environment. Now it is time to switch the Outlook clients to the target Exchange Online.
IMPORTANT: Client Update Agent may incorrectly switch the client profile during the transfer of the vanity domain name from the source tenant to the target tenant. It is not recommended to create a Mailbox Switch task during domain name transfers.
Create a Mailbox Switch Task:
- Open Mailboxes.
- Select the migrated mailboxes.
NOTE: Only migrated mailboxes can be switched. Use filtering by Completed status to see all migrated mailboxes.
- Click Switch Mailboxes.
- Specify mail forwarding direction:
- From source to target – standard switching scenario. The clients are automatically switched to the target tenant and all mail sent to the source addresses is forwarded to the target.
- From target to source – reverse scenario. The users are connected to the source tenant and all email sent to the target addresses are forwarded to the source.
- Provide the custom domain name for forwarding, typically your corporate domain name. Click Next.
- Configure notification messages (optional), if necessary. See Configuring Notifications for Mailbox Owners for details.
- Schedule when the task will be started. See Task Scheduling for details. Click Next to view the task summary.
- Check selected options and name the task. Click Finish to save or start the task depending on schedule option selected.
The task is created. You can track its progress in the Tasks, view the summary on the Dashboard or monitor alerts and notifications in the Events.
Configuring Notifications for Mailbox Owners
On Demand Migration allows to configure notification messages that appear after successful switch in:
- in new target mailboxes and / or in original source mailboxes (used now) in case you have selected Source to target mail forwarding direction on Mail Flow page
- in "new" (destination) source mailboxes and / or in original target mailboxes (used now) in case you selected Target to source mail forwarding direction on Mail Flow page
The following can be configured :
- Sender's email address - specifies email to replay (optional). In case no replay needed you can skip this field. In this case no email address will be displayed in the message.
- Send from: - specifies sender that will be displayed to user
- Subject: - specifies message subject
- Message: - specifies message text (plain text only)
Once the users are matched/migrated, you can transfer the content of their OneDrive for Business storages to the target tenant.
Before starting the OneDrive migration, consider the following:
- Migration may take a considerable amount of time, depending on the volume of data in storages.
- We only migrate files and folders present at the source OneDrive when the migration is started. Any changes made on the source during and after the migration are ignored.
- Re-migration overwrites all files in the target OneDrive. If OneDrive for Business sync client is already switched to the target tenant, all files will be re-synced. The existing copies of files stored on the local machines will be moved to the Recycle Bin.
TIP: Due to the high ongoing costs, it is recommended to re-run the migration only in case of significant changes of the source content.
- Only sharing permissions that are specified directly for accounts and groups that have matches on target are transferred. Refer to Sharing Permission Considerations for details.
- If a user or group is migrated and they have files shared with the group members, they will not be able to see them after migration. This functionality is not supported by Microsoft. The sharing can be restored manually after the migration is finished.
- Previous file versions are only migrated if their size is 80MB or less.
- Custom file properties (metadata) are not transferred to the target.
- Preferred data location (PDL) information is ignored for Multi-Geo tenant migration.
IMPORTANT: SharePoint system account will be set in Modified by information for all migrated content.