Stellar Merge Mailbox for Outlook Technician

Merge Multiple Mailboxes to PST

An advanced mailbox merge utility to combine or join multiple mailboxes of different email clients into a single Outlook PST. It can merge mailboxes of popular online and offline email clients, such as Outlook,, Office 365, Notes, Gmail, Yahoo, Apple Mail, Entourage, and more, to new PST files while preserving the original files’ contents, structure, and hierarchy.

  • Combines online or offline mailboxes and Identity Folders with complete integrity.
  • Saves merged mailboxes in new PST while maintaining the folder hierarchy.
  • Supports Outlook 2021, 2019, 2016, 2013, 2010, and earlier versions

Stellar Merge Mailbox for Outlook Technician


Unify Multiple Mailboxes Seamlessly icon

Unify Multiple Mailboxes Seamlessly

The tool can merge multiple online and offline mailboxes or identity folders of popular email clients to create a single Outlook PST file. It can join up to 10 mailboxes while maintaining the original folder structure and contents intact. It does not alter the original mailbox or makes any changes to your existing email profile or mailbox data files.

Join Multiple Online Mailboxes icon

Join Multiple Online Mailboxes

Stellar Merge Mailbox for Outlook can join online mailboxes, such as, Office 365, Yahoo, and Gmail, together and create a new Outlook PST file. It connects to your online mailboxes using the login credentials you provide, fetches the mailbox, and merges them automatically.

Combine Offline Mailboxes icon

Combine Offline Mailboxes

The mailbox merge software can also combine two or more different offline mailboxes, such as Outlook (PST), Outlook Express (DBX), or HCL Notes, formerly known as Lotus Notes (NSF), and creates a new unified PST file containing all your mail items. You can then import this PST to your Outlook profile, Office 365, or Exchange Server to access all your mail items from a single email client.

Merge Identity Folders icon

Merge Identity Folders

The software can merge multiple identity folders of 20 popular email clients, such as Outlook Express, Windows Mail, Windows Live Mail, Thunderbird, Entourage, Spicebird, Pocomail, Apple Mail, Eudora, Mulberry, SeaMonkey, Netscape, ClawsMail, OperaMail, Mozilla Mail, Evolution, Sylpheed, Cone, Mutt, & Gnu Mail into a single PST file.

More Awesome Features

Merge Online and Offline Mailboxes icon

Merge Online and Offline Mailboxes

The software can merge two or more online and offline mailboxes and save them to a PST file at your desired location. For instance, you can join an offline PST, DBX, or NSF mailbox with Office 365,, Gmail, or Yahoo. This helps you centralize and back up all your mail items from multiple email accounts in one PST file, making it easier to manage your mail items and backups efficiently.

Merge Faster with Advance Filters icon

Merge Faster with Advance Filters

The mailbox merge software provides advance filter options to include or exclude mail items while merging two or more online or offline mailboxes and identity folders. For example, you can use the ‘Date Range’ filter to combine or exclude mail items received between a specified date range. Similarly, you can exclude or include mail items based on senders’ email addresses. This helps you filter out emails or mail items you don’t need from the final PST file, providing a cleaner, unified mailbox.

Backup, Organize, and Manage All Mailboxes icon

Backup, Organize, and Manage All Mailboxes

With Stellar Merge Mailbox for Outlook, you can combine all your mailboxes to a single PST and import the PST to your Outlook profile to centralize all your mailboxes. This helps you access, organize and manage all your mail items from different email clients or mailboxes in one place. You can also keep the merged PST file as a backup, which can help you quickly restore mail items if you lose access to your email accounts or mailboxes anytime later.

Generate Detailed Log Report icon

Generate Detailed Log Report

The merge mailbox for Outlook software generates a detailed log report containing detailed information, such as process, start and end time, source file, folder names, etc. You can save the log report at the desired location in text format with the date and timestamp for later review. This detailed log report helps you verify the mailbox merge process and check whether all mail folders are merged successfully.

Product Tour for Stellar Merge Mailbox for Outlook Technician

Technical Specifications

About Product

Stellar Merge Mailbox for Outlook Technician


Release Date

May, 2022


Multiple Users

Version Support

250 MB of free space





Language Supported


System Requirement

System <span>Requirement</span>


Intel-compatible (x86, x64)

Operating System

Windows 11, 10, 8.1, 8, 7


4 GB minimum (8 GB recommended)

Hard Disk

250 MB for installation files

Download Guides


Start Using Stellar Merge Mailbox for Outlook Technician Today With Our Free Trial.


 Start Using Stellar Merge Mailbox for Outlook Technician Today With Our Free Trial.



Yes, to successfully merge multi NSF mailboxes into a single Outlook PST file, you need to install both IBM Notes (formerly Lotus Notes) and MS Outlook on the computer where you want to perform the merging mailboxes procedures.


You can add up to 10 offline mailboxes/online mailboxes/Identity Folders at once. Adding more than ten mailboxes will trigger a 'Mailbox Limit Reached' warning message. However, after merging the first ten mailboxes, you can further merge the resultant PST file with other offline mailboxes/online mailboxes/Identity Folders as per your need.


You can add any combination of Offline, Online, or Identity Folder mailboxes. However, the total mailboxes for merge should not exceed the ten mailbox limit in a single merge process.


Stellar Merge Mailbox for Outlook can merge Outlook PST, Outlook Express DBX, and IBM Lotus Notes NSF offline mailbox files into a single PST mailbox.


You can use the advance filter options to include or exclude emails received between a specific date range. You can choose the start date and end date and then select whether you want to include or exclude only those emails from the PST mailbox during the merge process.


Merging time depends upon several factors, such as the number of mailboxes selected, the size of each mailbox, and network speed. If the mailboxes are large or more in numbers, it may take a while to finish the merge process. However, if the mailboxes are small or less in number, the software can merge them more quickly. The time also varies when you join online mailboxes as it takes more time when compared to offline mailboxes as the software has to download the mail items from the online mailbox server. In addition, a faster network connection can help boost the merge process.


After merging the required mailboxes as PST using Stellar Merge Mailbox for Outlook, you can open the PST directly in Outlook or import it via Import/Export wizard in Windows and Mac. You may also import the PST files in Office 365 and Live Exchange Server.


You can merge up to 10 mailboxes at a time or in one go. However, you can repeat the process and merge as many as you want or need. For instance, after joining the first ten mailboxes, you get a unified mailbox as a PST file. You may select this new PST file and nine more mailboxes to merge them into one PST.


After merging and saving the mailboxes in the PST file, the software displays a confirmation message with a link to Open Containing Folder. Click on it to open the location where the new Outlook PST mailbox is saved.


The software provides filter options that you may use to include or exclude mail items from the resultant PST file based on email ID or a date range.


Stellar Merge Mailbox for Outlook merges multiple mailboxes with complete integrity. It keeps the original mailbox structure, folders & files hierarchy, and contents intact during the merge process.


The software is compatible with Windows 7, 8, 8.1, 10, and 11. Thus, you can merge multiple mailboxes or PST files using the Stellar Merge Mailbox for Outlook Technician software on Windows 11.