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The manual migration of On-Premises Exchange to Office 365 is not a simple task to perform. Each step is crucial, and so one needs care and expertise to accomplish such migration. This blog is drafted for discussing the necessary Office 365 pre and post migration checklist to help users in performing accurate migration without any loss.

The pre-migration tasks which the user should perform to get a smooth migration from on-premises Exchange to Office 365 are divided into points. Let us discuss them.

Pre-Migration Checklist

  1. Prepare end users in advance

    Planning and preparation start with proper communication among the organization members. Before starting the migration project, each user should have complete information about the migration plan, how it is going to be executed, and what will be the impacts and changes within the organization due to this migration. Other important considerations of pre-migration check are migration day, time frame, and resource management. The plan should be discussed among the members on a rough basis to get ideas from different brains, and after the brainstorming, the administrator should draft a proper project plan for the migration without any discrepancies in it. You can use the checklist prepared by Microsoft for effective premigration planning. You can add or modify this checklist according to your requirements.

  2. Prepare On-premises Inventory

    Next pre-migration task is to prepare the inventory for the on-premises Exchange. The details you should have before the migration are:

    • Name of user mailboxes (shared resources) and their sizes & email addresses.
    • Storage locations, client (browser, operating systems, Office applications) versions, and configurations.
    • Network settings (DNS hosts, proxy and firewall configuration, internal switches, internet connectivity, intranet sites, and available bandwidth).
    • Online meetings, instant messaging, integrated application systems, configured DNS records, etc.
  3. Inspect Current Environment

    Some checks and reviews are required on the current on-premises Exchange environment.

    • Methods to create or synchronize the accounts.
    • Licenses needed by user accounts.
    • The requirement of backups/backup policies
    • Network capacity and its suitability for the migration.
    • Basic training requirements for end users.
    • Authentication criteria for user accounts.
    • Antivirus, Firewall, Routers upgrade requirements.
  4. Prepare of Data to be Migrated

    Before starting the migration, make sure that the data is ready. Some points to be check are:

    • Active Directory is updated.
    • Not-in-use accounts are removed.
    • UPN of the source and target environments match.
    • Email addresses are valid within proxy addresses attribute.
    • Archiving facilities required (offline or online) in the future.
    • Compliance requirements.
  5. Set up Office 365 Account

    It is the final task while planning the Office 365/Microsoft 365 migration. Set up your Office 365 accounts with the below-given considerations.

    • Get Office 365 subscription and license.
    • Verify domain names.
    • Configure – security permissions, applications for use, directory synchronization for Office 365 (optional), and single sign in (optional).
    • Perform test migration.

Once all the tasks in the pre-migration checklist are completed, perform the migration. You can use professional Office 365 Migrator tool to perform this task easily. After migrating all the desired data migrated to the Office 365 destination, ensure that the tasks in the next provided checklist (post-migration) are completed.

Post-Migration Checklist
  1. Perform Email Redirection and Caching

    After migration, the emails accounts of users need to be redirected to Office 365. Also, check the Outlook profile folders again and confirm whether the status is “This Folder Is Up To Date” for each folder.

  2. Assign Licenses to the Migrated Mailboxes

    The mailboxes migrated in Office 365 account must be assigned licenses as it will get disabled after a period of 30 days without any license assignment. So, for long term use, it is recommended to assign licenses to mailboxes as soon as possible.

  3. Create Autodiscover DNS Records

    Another important post-migration task is to configure Autodiscover DNS records in Office 365. Doing this would help the users to connect their user mailboxes to Outlook email clients as well as other mobile clients.

  4. Decommission the Source Environment

    Once you are confirmed that the mailboxes have successfully moved to your Office 365 account, have assigned licenses, and everything is working fine, then you can decommission the old on-premises Exchange Server. However, it is suggested that you decommission it only when no synchronization is expected in the future with the source, and permanent migration to target is accomplished.

Hence, these were the important considerations to follow before and after the migration of the on-premises Exchange to Office 365. Does it seem quite complex than the migration itself? Yes, it is, and if you want to avoid these multiple technical and complex steps, you can opt for a reliable third-party tool, Kernel Office 365 Migration. This tool performs migrate on premise to exchange in the simplest manner. It also integrates simple ways to carry out some pre and post-migration tasks. Let us know these features.

On-premises Exchange to Office 365 – Some Pre & Post Migration Tasks – Kernel Office 365 Migration
  1. Pre-Migration Analysis for Mailboxes and Public Folders

    This feature in Kernel Office 365 Migration helps users to get an estimate about the time needed to perform the migration (based on the size of data added for migration). It also displays information like Total Folders, Total items, Total size, Network Speed, and Migration Speed.
    Kernel Office 365 Migration

  2. Migrate Outlook Rules and Folder Permissions

    Users can utilize this feature in the tool to migrate the Outlook rules and folder permissions after the completion of the migration task.


Just like the migration task, the pre and post-migration tasks are also crucial. Many things are to be considered before and after performing migration from Exchange and Office 365. However, a professional tool like Kernel Office 365 Migration integrates many features to perform these tasks automatically.

Kernel Office 365 Migration