How to Migrate SquirrelMail to Office 365 & Move Email Data

Migrate SquirrelMail to Office365

Published By Aldrich Calvin
Anuraag Singh
Approved By Anuraag Singh
Published On August 9th, 2023
Reading Time 5 Minutes Reading
Category Migration, Office 365

SquirrelMail, once a popular email exchange tool that had a presence in the feature film “The Social Network,” got its last update a decade ago. Therefore, users must migrate SquirrelMail to Office 365 ASAP. 

The open-source nature of SquirrelMail allowed technical users to maintain some basic functionality, but now even they realize that the mailing service is already past its limits.

Moreover, businesses may want an upgrade to a service that satisfies email communication and provides other benefits. Office 365 is one of the best solutions to this problem. 

Before exploring the steps in the guide, let us make a case for moving SquirrelMail data.

Reasons to Transfer SquirrelMail to Office 365

The tremendous advantages of Office 365, coupled with the limitations present in ‌ SquirrelMail leave little to no doubt that migration is a necessity. The points mentioned below elaborate on the matter:

  • SquirrelMail has officially been discontinued and is no longer receiving updates. 
    • In contrast, Office 365 gets new features and functions regularly.
  • Known security issues like XSS vulnerability, and attachments directory traversal failure present within SquirrelMail make it an easy target for cybercriminals.
    • Office 365 on the other hand has the backing of the entire cyber defense mechanism of Microsoft which reduces the chance of falling victim to a cyber crime.
  • SquirrelMail is entirely web-based so a proper broadband connection is required to access or migrate SquirrelMail to Office 365 manually.
    • Whereas, Microsoft provides the desktop version of Outlook to work with emails offline.

Read More: Learn How to Connect Hostinger Domain to Office 365 with Email Configuration 

Apart from all of this Office 365 also gives access to other apps like Teams, Onedrive, etc Now it is well established that a data movement needs to be done let’s take a look at the basic method to do so.

Steps to Migrate SquirrelMail Emails to Office 365 Manually

Step 1. Sign in to your SquirrelMail email Account.

Step 2. Navigate to ‘Options‘ and access ‘Archive Settings.

Step 3. Customize the Download Archive format to your preference.

Step 4. Select the specific Emails you wish to migrate.

Step 5. Initiate the Download process by clicking the ‘Archive‘ button, located at the bottom right of your email list.

Step 6. Watch as the archive swiftly develops and downloads directly to a location in your system.

This was only the halfway point and we still need to move the local SquirrelMail data to Office 365. However, there is a catch, as the download data is in MBOX format users must first convert it into PST format. 

This can be done manually using powershell scrips but it is too technical. Therefore use the expert-recommended MBOX file format changer to proceed with the task.

Step 7. Once you have the PST file simply upload it to the Outlook Webmail or desktop variants as per your convenience.

These steps have certain limitations to them that users need to look out for.

  • The process is nonrepeatable you have to start from scratch every time you need to transfer data.
  • It is a time-consuming and indirect method that has many points of failure. Moreover, issues can arise without warning.
  • Multiple archiving requests can also result in permanent data loss. Additionally, as SquirrelMail is depreciated there is no means of contacting a support staff to resolve these issues.

Read More: Learn How to Connect GoDaddy Domain to G Suite Via A Guided Tutorial

Don’t worry as to overcome these drawbacks we have a better and more professional solution available.

Automated Method to Transfer SquirrelMail to Office 365

Using the simple GUI-based interface present in the SysTools IMAP to Office 365 Migrator anyone can complete data transfer in just a few clicks. No matter what your technical knowledge the robust algorithms within the tool can perform email migration in one go. Click on the buttons below to try out the tool for yourself.

The steps to use the advanced utility to migrate SquirrelMail to Office 365 are given below:

Step 1. Launch the tool on your PC and choose the IMAP option as the source and Office 365 as the destination.

Choose Source and Destination

Step 2. Scroll toward the Workload Section hit the checkbox next to emails and apply a Date-filter.

Add Date Filter

Step 3. In the Source tab select the Other from the dropdown menu In the IMAP Server option, enter credentials for SquirrelMail and validate.

Select Other

Step 4. Navigate to the Target page and validate your admin credentials for Office 365.


Step 5. Select a User Mapping method from either direct Import or download a template to make your own CSV file.

Add Users

Step 6. View, and Validate Users then Start Migration.

Start Migration

Some advanced features that make the tool a market leader in email transfer scenarios are-

  • Multi-platform capability: Software is available for both Windows and Mac devices.
  • Single or Bulk Migration: The tool works in all situations whether you have a single email or multiple.
  • Apply Accurate Filters: Users can pick and choose the exact data they want to move due to the advanced date filter options.
  • Delta Migration Facility: Even if any new emails come during the migration the tool has the ability to migrate them as well.


Users now have complete knowledge of how to migrate SquirrelMail to Office 365 easily. Moreover, in this detailed guide, we covered the reasons and explained why the manual method should not be used. Finally, we provided a sure-shot automated tool for the job.