Email Migration

Lotus Domino to Microsoft 365 IMAP Migration CSV Format Guide

Muhammad Talha Sep 30, 2026 868 views

Question details

The user needs the correct CSV file structure for migrating mail from Lotus Domino to Microsoft 365 via IMAP, alongside clarification on superuser credentials, 1 GB NSF size limits, and contact migration.

Lotus Domino to Microsoft 365 IMAP Migration CSV Format Guide

Product: Microsoft 365
Device & OS: not provided
Scenario: Migrating mailboxes and contacts from a Lotus Domino environment to Microsoft 365 using an IMAP migration batch.
Observed behavior: The user seeks the exact CSV columns required for the IMAP migration, confirmation on using superuser credentials, and steps to address NSF limits and Lotus Notes contacts.

Before you start

Verify that your administrator account possesses the necessary superuser credentials to access all source mailboxes on the Lotus Domino server before initiating the migration batch.

Solution 1Recommended

Prepare the IMAP Migration CSV File

Create a properly formatted CSV file containing the exact required columns to map source mailboxes to target Microsoft 365 accounts.

Microsoft 365 requires a specific set of column headers to correctly process IMAP migrations. Any deviation from this format can cause the migration batch to fail.

Set up the CSV headers

Open your spreadsheet application and create the following exact headers in the first row without spaces: EmailAddress, UserName, Password, IMAPServer, and TargetEmailAddress.

Enter the migration data

Populate the rows with the corresponding user data. For example: source1@domino.com, user1, password123, dominoserver.example.com, target1@contoso.com. Ensure the account listed has permissions to access the source mailboxes.

Save as CSV

Save the completed document as a Comma Separated Values (.csv) file. Ensure no hidden formatting or extra delimiters are included in the file.

Superuser Credentials: You can use a superuser account (admin credentials) in the Password column to access all source mailboxes, eliminating the need to collect individual user passwords.

Solution 2

Manage NSF File Limits and Synchronize Contacts

Address the 1 GB NSF file limitation and prepare Lotus Notes contacts for migration, as IMAP does not natively transfer them.

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Frequently Asked Questions

Do I need individual user passwords for the IMAP migration CSV?

No, you do not need individual passwords if you utilize superuser credentials. An admin account that has permission to access all source mailboxes can be used in the CSV to simplify the process.

What does the 1 GB NSF limitation mean during migration?

The 1 GB limit generally refers to the size of individual NSF files rather than the total size of a user's mailbox. Make sure to manage or archive large local files before attempting the migration.

Can I migrate Lotus Notes applications via IMAP?

No. Direct migration of Lotus Notes applications and local custom databases is not automated through IMAP. You must use specialized third-party migration tools or perform manual data exports.

How do I migrate my Lotus Notes contacts to Microsoft 365?

Because Lotus Notes contacts are commonly stored in local NSF files rather than on the server itself, IMAP cannot transfer them. Users should manually export their contacts to a CSV format and import them into Microsoft 365.

Migration & Recovery