Exchange 2010 is the most used mailbox server to manage the hybrid structure created by Microsoft. Hybrid migrations allow you to link the on-premises and the Exchange cloud into a single structure.
You can host an Exchange server with competitive vdi desktop as a service provider. But, with the legacy of Exchange 2010 ending, it is recommended to consider alternative migration methods.
An advisor is a tool that generates an Exchange to Office 365 migration plan by asking questions. It has most of the important migration plans.
But this tool is also meant for single-forest, single-domain structures. If you have a more complicated deployment you have to prepare everything by yourself.
Any migration process is challenging be it Exchange 2010 to 2016 Migration or Tenant to Tenant migration Office 365 SharePoint. Hence there are 3 basic methods for your organization to migrate Exchange 2010 to Office 365:
1. Cutover Migration:
Primarily, you will have to prepare your structure for the migration. This might not consume a lot of time but is very important. After that, you will have to do the following tasks:
- Updating your Exchange 2010 server to SP3.
- Disable unified messaging and directory synchronization.
- Enable and configure Outlook everywhere.
- Designate permissions to the accounts undergoing migration.
- Build a mail-enabled security group in Office 365.
- Complete domain verification in Office 365.
- Build a migration endpoint with the help of the Exchange Admin Center.
- Design and begin the cutover migration batch.
- Do post-migration cleanup to make sure the migration was a success.
2. Hybrid Deployment:
This method allows the coexistence of Exchange 2010 and Office 365. It is specifically useful if there is plenty of data for migration and the process estimates a lot of time.
Hybrid is the only basic method available for migrations having over 2000 mailboxes. The Hybrid structure is designed with the help of a dedicated Hybrid Configuration Wizard (HCW).
Some organizations use the Hybrid deployment as the final structure instead of the intermediate stage, which has users allocated to both on-premises and online structures, based on user requirements.
3. Manual method (PST import):
The final basic migration method is done by using the Office 365 PST Import Service. The primary intention is to exporting Exchange 2010 mailboxes to PST files, and later uploading them into Office 365 structure.
This method needs an admin to do a lot of manual work. Which involves building Office 365 structure practically.
The best way is the use PowerShell and New-MailboxExportRequest for exporting all mailboxes to PST. The PST files have to be in a file server or a shared mailbox.
From this section, you have to upload them to the Azure storage and build a CSV mapping file. The PST Import method uses the mapping file to send PST files to the appropriate user mailboxes.
Now, it is up to you and your organization to choose between these basic methods of migration as per requirements.