Migration Methodology

Exchange Online do not provide any dedicated connector for Lotus Domino, so before starting migration you have to consider the migration option carefully.

  1. IMAP Migration
  2. 3rd Party Tools

Plan Your Migration

  • User mailbox data size.
  • User mail data archive size.
  • Networking and Naming Services Planning.
  • Determine required tasks for configuring network and DNS.
  • Determine mail-enabled applications and plan for configuration.
  • Conduct bandwidth assessment to calculate migration velocity for mailbox data.

Do you need 3rd party tool for migration?

Though IMAP Migration Connector is available in the Exchange Online but you should be aware of capabilities and limitations according to your requirements before buying any 3rd party tool.

IMAP Migration Limitations

  • Can only migrate Emails, Mailbox Contacts (a maximum of 3 email addresses per contact are migrated), Calendar, Labels.
  • Can’t migrate Vacation Settings, Automatic Replies, Filters/Rules, Room Bookings, Shared Calendars, Cloud Attachments, Google Hangout links, Gmail Tags, Contact URLs, Custom Tags.
  • Can migrate a maximum of 500,000 items from a user’s mailbox (emails are migrated from newest to oldest).
  • The biggest email message size you can migrate is 150MB.
  • Folder Manipulation.

Here are some third-party migration tools and partners that can assist with Exchange migrations from third-party platforms:

  • Binary Tree: Provider of cross-platform messaging migration and coexistence software, with products that provide for the analysis of and the coexistence and migration between on-premises and online enterprise messaging and collaboration environments based on IBM Lotus Notes and Domino and Microsoft Exchange and Microsoft SharePoint.
  • BitTitan: Provider of migration solutions to Exchange Online.
  • Quest: Provider of on-premises and hosted migration and coexistence software, including pre-migration analysis and complete user and application coexistence. Full-featured migrations from on-premises Microsoft Exchange, IBM Domino, Novell GroupWise, Zimbra and other environments to Microsoft 365, Office 365, Exchange Online, and SharePoint Online.
  • Transvault: Provider of cloud office migration solutions to Microsoft 365 from Exchange and Notes. Transvault supports 23 different sources for migration and has products that deliver any size of project, complex email archive migrations, and PST management. The enterprise migration solutions are secure, compliant, efficient, and user-focused, and can be run both on-premises and in the cloud.

Mail Flow Coexistence

You have to be very careful while planning the mail flow coexistence, please refer to the following document;

Plan for third-party email coexistence with Microsoft 365

If you are just migrating all mailboxes then switch mail flow to Microsoft 365 (Exchange Online) and perform backfilling using 3rd party tool or IMAP, but if you are going to maintain both mail system for long time then you have to plan coexistence using Shared SMTP Namespace.

Microsoft 365 Tenant Provisioning

Once you have acquired Microsoft 365 Licenses you need to do the following tasks;

  1. Register and Verify your Domain e.g, Contoso.com
  2. Creating Users and Provisioning Licenses

Now users can login to Office 365 using portal.office.com or office.com

Tip ! Microsoft 365 has enabled “Security Defaults” by default which supports only Modern Authentication not Basic Authentication used by Legacy Applications & Devices. It’s recommended to upgrade your clients to newer versions which support Office 365 Modern Authentication otherwise you have to turn off “Security Defaults”

Switching Mail Flow to Microsoft 365 and Setting Up Connector

Now you can switch your MX record to Office 365 in order to leverage “EOP” antispam filtering service. After switching MX record now new emails will land at Office 365 but how you will deliver Email to the on-premise Domino user mailboxes?

Answer is simple, you will setup a connecter between Office 365 and Lotus Domino which will send unresolved recipients to Lotus Domino.

Mail Flow after switching MX record from Lotus Domino to Office 365

IMAP migration in the Microsoft 365 admin center (Method 1)

  1. Sign into the About the Microsoft 365 admin center.
  2. Navigate to Setup > Data migration.

3. Select other email sources dashboard opens.

fill in the appropriate IMAP connection data to test the connection. You can use any account for this.

4. Click Save to test the connection. Once the connection is verified, the Email Migration Status page will list all your added users with the email address that you provided.

5. Choose Start Migration after you have entered the required information.

Migrate other types of IMAP mailboxes to Office 365 (Method 2)

  1. Note down the IBM Lotus Domino Server Information for IMAP
  2. Create *.Csv file for users to be migrated.

Use the following screenshot as a template to create the migration file in Excel. Start with the headings in row 1. Make sure they match the picture exactly and don’t contain spaces. The exact heading names are:

  • EmailAddress in cell A1.
  • UserName in cell B1.
  • Password in cell C1.

Tip ! Lotus Domino don’t support Administrator Account Impersonation, so you can’t migrate user mailboxes from Lotus Domino to Exchange Online using single Admin account instead you have to specify password for each user.

Connect Office 365 to IBM Lotus Domino

  1. Open the Exchange admin center.
  2. Go to Recipients > Migration > More More icon > Migration endpoints.
  1. Click New New icon to create a new migration endpoint.
  2. On the Select the migration endpoint type page, choose IMAP.
  3. On the IMAP migration configuration page, enter the following information:
    1. * IMAP server: Type the messaging server name (for example, imap.contoso.com) of the source email server.
    2. Leave the remaining information as the default settings; these will work for most cases.
  4. Click Next. The migration service uses the settings to test the connection to your email server. If the connection works, the Enter general information page appears.

On the Enter general information page, type a Migration endpoint name, for example, Test5-endpoint. Leave the other two boxes blank to use the default values.

5. Click New to create the migration endpoint.

Create a migration batch and migrate mailboxes

  1. In the Exchange admin center, go to Recipients > Migration.
  2. Click New New icon > Migrate to Exchange Online.
  1. Choose IMAP migration > Next.
  2. On the Select the users page, click Browse to specify the migration file you created. After you select your migration file, Office 365 checks it to make sure of the following:
    1. It isn’t empty.
    2. It uses comma-separated formatting.
    3. It doesn’t contain more than 50,000 rows.
    4. It includes the required attributes in the header row.
    5. It contains rows with the same number of columns as the header row.

If any one of these checks fails, you’ll get an error that describes the reason for the failure. If you get an error, you have to fix the migration file and resubmit it to create a migration batch.

  • After Office 365 validates the migration file, it displays the number of users listed in the file as the number of mailboxes to migrate.
  • Click Next.
  • On the IMAP migration configuration page, click Next.
  1. Click Next.
  2. On the Start the batch page, do the following:
    1. Click Browse to send a copy of the migration reports to other users. By default, migration reports are emailed to you. You can also access the migration reports from the properties page of the migration batch.
    2. Choose Automatically start the batch. The migration starts as soon as you save the new migration batch. The batch status is first Created and changes to Syncing after the migration starts.

Verify that this task worked

In the Exchange admin center, go to Recipients > Migration. Verify that the batch is displayed in the migration dashboard. If the migration completed successfully, the Status is Synced.


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