Exchange to Office 365 migration

Exchange server vs Office 365

Compared to the Exchange server, Office 365 includes advanced features such as Email Archiving, Retention Policies, Encryption, Backup and Recovery, Auditing and Reporting, Mobility, Email access from multiple devices, Email access from web. The following table highlights the differences between Exchange and Office 365.

Exchange online is a part of Office 365 and you can also switch to a stand-alone Exchange online plan without the Office 365 productivity suite. Before you switch from Exchange server to Office 365, it is highly recommended that you get familiar with the 365 suite features, compare and choose the license plan best suited to your requirements.

 In this guide, we describe the pre-migration activities, the different migration paths from Exchange to Office 365 and the post migration activities.

What is the best way to migrate from Exchange server to Office 365?

EdbMails Exchange to Office 365 migration tool is the perfect solution if you are looking to migrate Exchange server mailboxes to Microsoft 365. It can migrate emails, contacts, tasks, journals, appointments, calendars, notes from the source to the target with complete data consistency. It can help you migrate multiple user mailboxes, private and public folders, shared and archive mailboxes, room and equipment mailboxes without requiring any PowerShell scripts or technical knowledge. It is easy to use, fast and a user-friendly tool to accomplish mailbox migrations to the cloud.

I. Exchange to Office 365 migration checklist

Moving to Office 365 from Exchange can be challenging if you have a large number of mailboxes and data to migrate. The following points can help you safely transfer all your mail data to the cloud without a hassle.

1. Plan for the migration:
   • Identify the scope of the migration, including the number of mailboxes, public folders, and other data that needs to be migrated.
   • Determine the size of the mailbox data and number of mailboxes to migrate.
   • Assess the current environment, including hardware, software, and network configurations.
   • Prepare a complete inventory of items that you want to migrate.
   • Determine the migration schedule, including the timing and duration of the migration.
   • Identify any specific requirements or constraints that may affect the migration.
   • Communicate any changes to your end users and inform the stakeholders.
2. Prepare the data for migration:
   • Perform a full Exchange server backup and all related data.
   • Clean up and archive any unnecessary data to reduce the amount of data that needs to be migrated.
   • Perform a test (pilot) migration to identify and resolve any issues before the full migration.
3. Purchase and configure Office 365 licenses:
   • Purchase the necessary Office 365 licenses for all users that will be migrated.
   • Configure the Office 365 tenant, including creating and configuring users, mailboxes, public folders and other resources.
4. Configure the domains and DNS records:
   • Prepare the domains and required Active Directory services on the target.
   • Update the DNS records to point to the Office 365 tenant, including MX records and Autodiscover.
   • Verify that the DNS changes have propagated and that email is flowing to the Office 365 tenant.
5. Perform Exchange to Office 365 migration with EdbMails:
   • EdbMails can help you with Exchange migrations to the cloud
   • Configure the migration settings and migrate mailboxes, Public folder and Shared mailboxes.
   • Monitor the migration progress and verify the migrated items
6. Test and validate the migration:
   • Test the migration by sending and receiving email and verifying that all data has been migrated correctly.
   • Validate the migration by checking for any missing data or issues, and troubleshoot as needed.
   • Perform a final backup of the Exchange server before decommissioning it.
7. Post-migration tasks:
   • Update email client settings, such as Outlook, to point to the Office 365 tenant.
   • Create new Outlook profiles and check if you are receiving mails correctly.
   • Update any custom scripts or applications that access the email data to point to the Office 365 tenant.
   • Update any third-party services or integrations that access the email data to point to the Office 365 tenant.
   • Update the helpdesk and end-user documentation to reflect the new email environment.
   • Train users on the new email environment and any new features or functionality provided by Office 365.
   • Decommission the source Exchange server if you no longer plan to use it (optional).
8. Monitor and maintain:
   • Monitor the Office 365 environment for any issues or performance problems.
   • Maintain and update the Office 365 environment as needed.
   • Continuously review and improve security, backup, and disaster recovery strategies.

II. Exchange to Office 365 migration plan

• Step 1: Decide on a suitable Exchange to O365 migration type

  The first step is to plan the Exchange mailbox migration to Office 365. Depending on your source and target environments, the following migration paths are available.

  Migration Requirement	Ideal migration approach	Migration flow
  You want to move all of your email, calendar, and contacts from Exchange to Office 365 at once.	Exchange cutover migration	In this migration type, you set up your target Office 365 tenant and migrate everything to the cloud all at once. Suitable for large-scale mailbox migrations
  You prefer to transfer mailboxes from Exchange Server to Office 365 in smaller batches or on weekends.	Staged Exchange migration	In this type, you migrate your mailboxes and mail data in stages, transferring the most recent data first, followed by the others.
  You want to retain your on-premises Exchange server and prefer moving to Office 365 gradually	Hybrid migration	In this migration type, you move mailboxes to Office 365 in a Hybrid deployment of Exchange and Office 365.
  You want to migrate from a legacy Exchange such as 2003, 2007 or 2010 to Office 365 or when you do not have access to your Exchange server.	EDB or IMAP migration method	In this migration type, you migrate mailboxes with an EDB file or by using an IMAP connection.

   Use the Microsoft 365 mail migration advisor to determine which migration method is best for you.

• Step 2: Install cumulative updates (CU) on the Exchange server

  Ensure that you have the latest updates installed on the source Exchange.

  1. Install CU for Exchange server 2010
  2. Install CU for Exchange server 2013
  3. Install CU for Exchange server 2016
  4. Install CU for Exchange server 2019
• Step 3: Consider the network and bandwidth requirements
  1. Network requirements
     1. Understand the networking roadmap for Microsoft 365. It involves planning, deploying and managing your network.
     2. Internet Connectivity: A stable and reliable internet connection is required for migration of Exchange to Office 365. The internet connection should have sufficient bandwidth to handle the data transfer and should be free from congestion.
     3. Firewall and Port Configuration: Review and configure the firewall and port configurations to allow for the necessary data transfer to the Office 365 tenant.
     4. DNS Configuration: Review the DNS records and configure them to point to the Office 365 tenant, including MX records and Autodiscover. This task ensures that email is properly routed to the Office 365 tenant after the migration.
     5. Network Latency: Consider the Network Latency to ensure a seamless data transfer. If the Network Latency is high, it may slow down the migration process. See how Microsoft 365 networking is different.
     6. Office 365 Throttling: Microsoft limits the number of concurrent mailbox transfers to ensure service availability. Consider the Office 365 throttling policies when you migrate large mailboxes.
     7. Network Security: Review the network security to ensure that the data transfer is secure. This includes configuring any necessary encryption, authentication, and access controls.
     8. Network Load Balancing: Consider the Network Load Balancing to ensure that the data transfer is balanced across multiple networks and to avoid any bottlenecks.
  2. Bandwidth requirements

     Bandwidth requirements for Exchange to Office 365 migration can vary depending on several factors, such as the number of mailboxes, the amount of data to be migrated, and the migration method used. Use tools like Microsoft Remote Connectivity Analyzer and connectivity test tool to test your existing network.

     1. Number of mailboxes: The number of mailboxes being migrated influences the overall bandwidth requirements. The more mailboxes you plan to migrate, the more bandwidth you will need. See bandwidth requirements for Office 365 migration.
     2. Mailbox Size: The size of the mailboxes being migrated also influences the overall bandwidth requirements. Larger mailboxes will require more bandwidth to migrate.
     3. Migration Type: The type of migration you use also affects the bandwidth requirements. For example, a cutover migration, where all mailboxes are migrated at once, requires more bandwidth than a staged migration, where mailboxes are migrated in smaller groups.
     4. Migration schedule: The schedule of the migration also influences the bandwidth requirements. For example, migrating during off-hours or over a weekend when network traffic is typically lower, reduces the overall bandwidth requirements.
     5. Network infrastructure:. A network with higher bandwidth capacity can handle more data during the migration.
     6. Network Latency: Network Latency between the source and destination servers is also a factor to consider during the migration. If the Network Latency is high then a higher bandwidth is required.

      See best practices for network planning and improving migration performance.

     Note: If you have already configured your Office 365 tenant, you can directly skip to Step 7 in this section.

• Step 4: Select a suitable Microsoft 365 license plan that fits your needs

  Microsoft 365 is available as a cloud-based subscription service and offers a variety of licensing options, each tailored to a specific user's needs. It is recommended that you thoroughly evaluate the Office 365 business plans and Office 365 enterprise plans to determine which one best meets the needs of your organization. You can also sign up for a 30-day free trial of Office 365 to test out the various plans before making a final decision

• Step 5: Set up your target Office 365 tenant for the migration
  1. Create an Office 365 tenant: Plan for the tenant implementation and deploy the tenant. See the tenant roadmap for Office 365.
  2. Sign in to the Microsoft 365 admin center: Go to the Microsoft 365 admin center (https://admin.microsoft.com/) and sign in with your global administrator credentials.
  3. Customize the tenant settings: After the tenant is set up, you can configure and customize the settings such as email domains, language, and time zone to suit your organization's needs.
  4. Configure Azure AD Connect: Azure AD Connect is used to synchronize your on-premises Active Directory with Azure AD. This step is necessary if you want to retain your on-premises in a Hybrid environment and to enable single sign-on (SSO) for your users.
  5. Configure email clients and apps: If you want to install Office 365 apps and Outlook, see system requirements for Microsoft 365 and Office configuration support matrix. Because Office 365 is a cloud based solution, it is also important to learn where your Microsoft 365 customer data is stored.
  6. Set up Office 365 services: Besides email, you may want to set up additional services such as SharePoint, OneDrive and Teams.
  7. Establish data retention policies: With Office 365, you have the ability to retain data in accordance with compliance and legal requirements. Set up data retention policies to meet your organization's compliance needs, and if necessary configure retention policies for specific mailboxes or groups of users
• Step 6: Add and verify the custom domain on Office 365

  If you have a custom email domain from your hosting provider to which you want to migrate and receive emails, you must add and verify the domain on Office 365. This will enable you to use your own domain name (such as example.com) for your email addresses and other Office 365 services.

   To set up your custom domain, follow these steps:

  1. Verify that you own the domain by adding a TXT record to your DNS configuration.
  2. Add a new domain to your Office 365 tenant. You can use an existing domain that you own or purchase a new one. The domain is used to access your Office 365 services.
  3. Update your DNS records to point to Office 365. This step is required to ensure that your email is delivered to the correct mailbox. You can also update the MX records after you complete the migration.
• Step 7: Create mailboxes and set up mail-enabled Public folders

  Before you migrate to Office 365, ensure that you create mailboxes for users in your organization and assign suitable licenses to them.

  1. Add users and assign licenses to Office 365 users
  2. Add several users at the same time to Office 365
  3. Assign Microsoft 365 licenses to user accounts

  Create and configure Public folders and make them mail enabled on Office 365.

  1. Create Office 365 Public folder and assign mailbox user
  2. Enable In-Place Archive mailboxes in Office 365
• Step 8: Set the impersonation role to the admin user on the source

  Ensure that you set the following permissions to the admin account on the source and target server and that the mailboxes you migrate are not hidden from the address lists.

  1. On the source
     1. ApplicationImpersonation
     2. View-Only Configuration - Run the cmdlet New-ManagementRoleAssignment using the Exchange Management Shell to assign the View-Only Configuration role to the admin.
  2. On the target
     1. ApplicationImpersonation

  Setting impersonation rights in Office 365 is a simple process that can be done quickly using the Admin Center. Assign the Organization Management role group to the admin user in Exchange online. It is an elevated permission that is required to migrate Public folders.

• Step 9: Verify the mailbox of the admin account

  Check to see if the admin account that has been assigned management roles has a valid and non-hidden mailbox on the Exchange 2016 server. See how to configure user mailbox properties for the users from the Exchange admin center (EAC).

• Step 10: Configure Office 365 to send and receive large messages

  Increase the message size limit on Office 365 to 150 MB. This option enables you to bypass message size limitations during the migration.

Difference between Microsoft and EdbMails migration methods

Both Microsoft migration method and EdbMails support all the Exchange migration types such as cutover, staged, hybrid and IMAP. However, there are mailbox limitations and downtime if you plan to migrate with the Microsoft method. For example, Microsoft's cutover migration process is much slower and less efficient than EdbMails cutover migration. EdbMails is a simple approach for Exchange migration that enables you to transfer mailboxes and folders without size restrictions or downtime.