
Introduction
Leaving IBM Lotus Notes is a little like running through a maze. Lotus Notes uses a proprietary NSF file format, so you need a dedicated tool to move your archived emails, attachments, and folder structure to modern open clients such as Thunderbird or Apple Mail.
In this review, we will conduct a thorough hands-on test of the WholeClear NSF to MBOX Converter (Official Site) with 10 real NSF files containing over 2,500 emails. Here’s our in-depth look at how it did.
Find out about the file formats.
It is helpful to know why this conversion is needed before you take the test:
NSF (Notes Storage Facility): IBM/HCL Lotus Notes proprietary database format. It contains emails, calendars, contacts, and tasks, but is notoriously difficult to get into outside of the Notes universe.
MBOX: A standard format used for storing a collection of electronic mail messages. It is natively supported in open-source and cross-platform email clients like Mozilla Thunderbird, Apple Mail, Eudora, and SeaMonkey.
Test scenario from my side
In our test scenario, we tested the overall conversion workflow with 10 NSF files with 2500+ emails. “The big thing we wanted to know was whether the software could make migration easier and still retain important mailbox data.”
The results are:
Dataset Size: No problem processing more than 2,500 emails from 10 NSF files
Pre-Conversion Verification: The software offered a detailed preview window before migration so we could see mailbox contents.
Attachment Security: The export process was run against all email attachments.
Metadata Fidelity: Critical metadata, including To, CC, BCC, subject, sent/received dates, and rich-text formatting, were fully preserved.
Lotus Notes Mailbox Internal Folder Hierarchy Preservation.
Target Compatibility: Output data was successfully saved in MBOX format and verified in Mozilla Thunderbird and Apple Mail.
Source Safety: The original NSF files were not altered or compromised in any way in the process.
Simple workflow: The process only involved three easy steps: Add NSF -> Choose Destination $\rightarrow$ Begin Conversion.
The Software Solution and How It Solves the Problem
Changing a file extension is not migrating email. The key challenge is to migrate thousands of emails while maintaining their organisation, context, and formatting. WholeClear fills the gap between the closed environment of Lotus Notes and MBOX-compatible clients.
Main Features
NSF to MBOX Conversion: Export Lotus Notes databases to the most popular MBOX files easily.
Attachment & Metadata Retention: Exports messages with attachments and retains properties such as To, CC, BCC, and timestamps.
Keep Folder Structure: Maintains your current folder hierarchy.
Preview Mode: Enables you to preview and verify mailbox items before the final conversion.
Single File/Folder Mode: This mode enables the addition of either single files or a collection of folders that contain NSF files.
Flexible Output Option: User can choose single or multiple MBOX files.
Supports Different Lotus Notes Versions such as Lotus Notes 10, 9.1, 8.5, 7.0, 6.5, etc. Windows OS versions including Windows 10, 8, 7, and XP.
Conversion Process (Step-by-Step Manual)
The software is easy to operate. Here’s how the 6-step workflow looks in action:
Step 1: Launch & Prerequisite Check: Make sure that the Lotus Notes is installed in your Windows PC. Launch the WholeClear Converter application.

Step 2: Select NSF files: Either select the individual NSF files in File Mode or browse and import the NSF files from the folder in Folder Mode.

Step 3: Scan & Preview: Let the application scan the database. In-built viewer allows you to preview emails, folders, and attachments.

Step 4: Select Output Format: Choose MBOX as the format in which you wish to save the converted file.

Step 5: Set Settings: Choose whether you wish to generate a single merged MBOX file or different MBOX files for each NSF database. Also, set your destination folder path.

Step 6: Start Conversion: Hit the “Convert Now” button and watch the progress bar complete the conversion process.

Results and discussion
The test showed that WholeClear lives up to its core promises. The software created a bridge between IBM’s ecosystem and open source clients without the need for complex manual scripting.
Some notes on operation for the user to note:
Requirements: Lotus Notes must be installed and configured on the conversion machine. The source NSF files must be non-corrupted.
Trial Limitation: The free demo version can convert only the first 25 emails from each file. Therefore, for large-scale migrations with more than 25 emails, you need to buy the full license.
End of story
WholeClear NSF to MBOX Converter is the ultimate combination of user-friendliness and high data integrity. It automatically handles attachments, folder hierarchies, and rich text formatting, saving IT administrators and everyday users hours of manual work moving away from Lotus Notes.
Conclusion and Call to Action
If you are leaving Lotus Notes and heading to MBOX-supported clients such as Thunderbird or Apple Mail, WholeClear offers a trusted, straightforward way ahead for your organization/personal workflow.
Feel brave? Want to have a go? Try the first 25 emails on your own dataset today! Download the free trial version from the WholeClear NSF to MBOX Converter Page.
FAQ: Frequently Asked Questions
1. Do I need to install Lotus Notes on my computer to use this converter?
Yes. WholeClear works on Lotus Notes API background dependencies to read and interpret the proprietary NSF file structure. It is required to install and configure Lotus Notes on the same system to make the tool work.
2. Will I lose my email attachments and folder structure during the conversion?
No. Specifically designed software saves original folder hierarchies, inline images, rich text formatting, and all associated file attachments.
3. How to convert NSF files in bulk?
“Yes. The software has a folder mode option, which helps to process multiple NSF databases in one go.
4. What’s the difference between the free trial and the licensed version?
A free demo version of the software is available to convert the first 25 emails of each NSF file free of charge. This restriction is removed in the licensed version, and unlimited bulk migrations are allowed.