Mimecast to Office 365 migration

Without a doubt, Mimecast provides enhanced security and serves as an additional security layer for data protection. However, as businesses merge or are acquired, the newer management may prefer to do away with the existing infrastructure or simply plan to have everything in one place. Let's take a look at why and how to migrate to Office 365.

• For the same price, Office 365 already includes in-place archiving, eDiscovery, search, and export which helps many businesses in avoiding additional costs.
• Office 365 also includes Microsoft Defender, Exchange online protection, robust security, and advanced spam filters that are integrated with email.
• Mimecast may not allow certain emails to pass through when configuring Office 365 emails with other services, resulting in delivery failures.
• Instead of relying on external third-party services, organizations are implementing in-house firewalls and blocking methods.
• When an organization requires immediate access to the archives, exporting data from Mimecast becomes difficult.

Planning is one of the most important steps before you begin the Mimecast to Office 365 migration. Here is a checklist of points to consider before you migrate.

• Determine the size of the data and the number of mailboxes you want to migrate.
• Make a list of all the data and permissions from the Mimecast that you want to transfer.
• Create appropriate user mailboxes on Office 365 and assign licenses to them.
• Ensure you have enough network capacity and bandwidth to migrate.
• Communicate the migration plan and flow to your end users.

• Create Office 365 mailboxes and assign licenses to them

   Add users and assign licenses to Office 365 users

   Assign Microsoft 365 licenses to user accounts

• If you plan to migrate the Mimecast archive to Office 365 Public folders, ensure that you create and configure the Public folder mailboxes on the target server.

   Create Office 365 Public folder and assign mailbox user

• Similarly, if you want to migrate to the Office 365 In-Place archive, enable them from the admin center.

   Steps to enable archive mailbox in Microsoft 365.

• If you have a custom email domain from the source which you want to retain and receive emails to, you must add and verify the domain on Office 365.

   Steps to add a custom domain to Office 365 and Steps to add DNS records to connect your domain.

• Configure Office 365 to send and receive large messages.

   Follow the steps to increase the message size on Office 365 to 150MB. See message size limits on Office 365 for more information.

• Step 1: Download and install the EdbMails software

  • Download and install the EdbMails application on a Windows-based computer to begin the migration process.

    

  • See a detailed list of EdbMails system requirements for PST to Office 365 migration.
  • Launch the application and log in with your registered email and password. If you're new to EdbMails, click on ‘Start Your Free Trial’ to access the application instantly without creating an account.

    

  • Select ‘Outlook PST Recovery and Migration'.

    

  • Select ‘PST to Office 365’.

    

  • You can either proceed with the default job name or click ‘New Job’ to assign a custom name for easier identification. Once done, click ‘Next’ to continue.

    

• Step 2: Select the offline PST file and connect to the source

  • Before you begin the migration, ensure that your mailbox data from Mimecast is exported in PST format.
  • To import a PST file into EdbMails, click on ‘Browse for PST file’.

    

  • Select the offline PST file from your computer’s local drive that you want to migrate. After choosing the file, click ‘Next’ to continue with the migration process.

    

• Step 3: Preview and select the Mimecast mailboxes

  • EdbMails automatically scans the PST file and recovers data even if the file is partially corrupted, ensuring a reliable and complete migration.

    

  • Once the recovery process is complete, the full mailbox folder structure will be displayed in the left pane. You can navigate through folders and subfolders to explore the recovered data. EdbMails built-in preview feature allows you to view emails, contacts, calendars, and other mailbox items directly within the application, ensuring accuracy before migration.
  • Select the required mailboxes/folders for migration and click the ‘Next’ button.

    

• Step 4: Connect to target Office 365 server

  • Click the ‘Add New Connection’ button to establish a new connection to the target Office 365 server. To use the previous connection, select it from the connection list and click the ‘Connect to Existing’ button to proceed.

    

  • Choose the appropriate connection settings based on your migration needs, then click ‘Next’ to proceed.

    

  • Select the one of the authentication methods and click the ‘Login’ button to continue.

      Connect to Office 365 server using secure modern authentication

    

  • Authenticate on Microsoft sign-in page.

    

  • Select one of the methods to load the mailboxes. You can also load the mailboxes using a CSV file.

    

• Step 5: Mimecast to Office 365 source and target mailboxes mapping

  • Choose the required mailbox mapping option.

    

  • EdbMails automatically creates mailboxes on your target Office 365 server and assigns the necessary licenses.

     Learn more about the automatic mailbox creation process on the target Office 365 server.

  • By default, EdbMails automatically maps the mailboxes and folders between the source and the target server. You can also manually map the source mailboxes to the required target mailboxes.

    

• Step 6: Start Mimecast to Office 365 migration

  • Click the 'Start Migration’ button to initiate the migration process.

    

  • The migration will now start, and you can monitor its progress through the status bar. EdbMails allows you to pause or resume the process at any time. Once completed, a confirmation message will appear indicating a successful migration.

    

  • You can verify the list of migrated folders and mailbox items with EdbMails text-based migration log report.
  • Once the migration is completed, log in to your target Office 365 account and verify that all the mailbox items have been migrated correctly.

• Step 1: Update the MX records to point to Office 365

  If you have not done this step previously, change the DNS records known as MX records to enable email and receive messages on the target Office 365 server. In addition, configure the Autodiscover record to allow Outlook to connect to the migrated mailboxes.

• Step 2: Create a new Outlook profile for users in the new domain

  Configure the Outlook profile for each user in your domain if Outlook has problems connecting to Office 365 mailboxes.

  Refer to the knowledge base articles for solutions to common issues. For additional details on EdbMails PST to Office 365 migration, check the frequently asked questions or reach out to our customer support team.