Easily Import PST to Fastmail Without Data Loss

  

Mark Regan
Published: January 13th, 2026 • 6 Min Read

If you are searching for the solution to Import PST to Fastmail with email attachment, then this guide will help you to import easily. In this blog post we are going to describe both workable manual and professional solution to open PST to Fastmail. At the end of this blog, you will do import easily without data loss and complete data integrity.

Fastmail is a globally used email service, it’s also popular for its security. It offers two account types that is free and paid. Some users who want to switch their email communication method they choose this platform for better email management. The Fastmail is easily accessible from anywhere with simple internet connection. On the other hand, the PST files require an email client to open.

Now the question arises: can I Open PST files in Fastmail? In the next section we are going to answer to this quarry.

Can I Open PST File in Fastmail Account

So, the answer of user’s quarry is “No.” You cannot open PST file in Fastmail account directly. To open PST file in Fastmail you need to convert PST files in to MBOX format first, then you can import PST to Fastmail Account.

Moving on the import process of PST file to Fastmail account, that is in next section.

How to Import PST to Fastmail Manually

To manually import PST to Fastmail, you must carefully follow the detailed step-by-step instructions listed below.

Step 1. Import PST files into Outlook

1. Run the Microsoft Outlook application on your computer.
2. Open the navigation menu and select “File” option.
3. Then, select “Open & Export” option.
4. Now, click on the “Import/Export” button.
5. After that, select option “import from another program or file” and click “next.”
6. Select “Outlook Data file (.pst)” option.
7. Now, browse the file in your computer systems.
8. Finally, click on “Finish” button.
9. Afterwards, “Drag” that imported file into your main Outlook account.

Now, let’s move to step 2.

Step 2. The Use of Thunderbird for MBOX

1. To create PST files, you need to convert PST to MBOX format first.
2. Download and install the Thunderbird application.
3. Run the application on to your computer.
4. Connect your any email account inside the application.
5. Now, go to navigation bar and click on “Tool” option.
6. Then, you will see the import option, click on “import” button.
7. After that, click on Continue button.
8. Tick mark the suggested folders as per your need.
9. Click on Continue button to move the next page.
10. Finally, you reached to final page here click on “Start import” button.
11. Done! The thunderbird will automatically import all your Outlook data.
12. Additionally, it also stores your email data in separate folders in the thunderbird.

Now, let’s move to Step 3.

Step 3 Installation of Add on Extension

1. Go to the gear icon inside the thunderbird to open settings.
2. After that, open the tab of “Add-ons and Themes” and find “ImportExportTools NG.”
3. Now, open the suggested extension and click to add.
4. Done! Your Installation process is done.

Now move to the step 4.

Step 4. Creation of MBOX File in Thunderbird

1. Move to the created folder by using step 2.
2. Now, right-click on the existing folder.
3. After that, in the last step you will see the option “ImportExportTools NG”, click on it.
4. Then, choose the option “Folder Export.”
5. Here, you will see a new option as name “As MBOX file.”
6. Click on that “As MBOX file.”
7. Then, set the file destination to save your files.
8. Done! Your MBOX file is ready to use.

Now move to the step 5.

Step 5. Import on Fastmail Account

1. Open your Fastmail Account in your any web browser.
2. Login into your account using your Fastmail Account Credentials.
3. Then, in your account dashboard you will see the gear icon click on that.
4. After that, go to the “Migration” menu, and click on “HEY (upload MBOX file)” option.
5. Now, click on Upload file button to upload just created MBOX file using method described in step 5.
6. Done! Wait for few minutes your files will we add in your Fastmail account.

By following the above step-by-step instructions carefully, you will import PST to Fastmail account.

Before moving forward, it’s important to be aware of the limitations of this manual solution before using it, as described in the next section.

Limitations of Using Described Above Solution

• High risk of losing data integrity.
• The working process is lengthy, and time-consuming
• It has multiple steps, that will confuse any users and may work well properly.
• To use this method users, need to have tech knowledge.
• Any single mistake in the described in every single step will lead to data loss.
• Converted file will loss the attachments of emails.
• Not good for batch files, or large size of email data.
• These methods can be failed in some cases to import data.

These were the main limitations of using the described manual method to import PST in Fastmail. However, if the above-described methods will not work then you can try next method below.

How to Import PST to Fastmail Professionally

If the above-described method doesn’t work well and give you a desired result. In such case, you can use the BitRecover PST Converter program to import PST file easily. It’s easy to use interface directly import PST files to Fastmail account with data integrity.

Download the trial version of for free and check it’s working.

To know the complete process and direct solution to impot PST to Fastmail you only need to check out describe steps by step method below.

Steps to Import PST to Fastmail Account

1. Open the application on your windows or Mac PC.
2. Then, click on the NEXT button to start the process.
3. Here, selects one option from Select Files or Select Folders.
   
4. Find the PST file in your local folder, open it in the program and click “NEXT.”
   
5. Then, select IMAP as a Saving option from the toolkit.
   
6. Enter your Email Address, Password and IMAP Host.
7. Check mark the option “Use Batch Mode” (if you need batch conversion).
8. Finally, click on convert button to start the conversion process.

These steps will help you easily Import PST to Fastmail account.

Benefits of Using Professional Method

1. Selective import option for your PST files.
2. Data Integrity will be maintained during import process.
3. Direct Import to Fastmail account without following any detailed steps.
4. Utility prevents attachments while importing PST to IMAP.
5. Compatible with all versions of Windows OS 11, 10, 8.1, 8, 7, XP and MacOS
6. No need high technical knowledge to use this utility.

Final Thoughts

In this blog post, we described the Import PST to Fastmail is easy. We used two methods to import PST file into Fastmail. Found using manual method is time-consuming, lengthy and requires high tech knowledge. However, using the suggest mentioned program the import in Fastmail become easy. Additionally, this utility saves times and import all the PST files with attachments and complete data integrity in just a few clicks.

If you are looking for instant solution to import then you should try the trial version of suggested tool, if you satisfied with the results you can go with its licensed version.