Email Migration Tool for Windows: Import PST to Gmail and Office 365

How to download and use the Email Migration Tool for Gmail and Office 365

Add your mail files

Download the Email Migration Tool and install it. Click Add files and pick your PST, MBOX or EML files. Add folder takes a folder of EML files with its subfolders. Files are only read. Nothing in them is changed.

Choose the mailbox and sign in

Pick the destination under Email service. For Gmail, type your address, fill in the App password field and click Connect. For Microsoft, type your address, click Sign in with Microsoft and enter the password on the Microsoft page. Wait for the status to say Connected.

Tick the folders and set the destination

Tick the folders on the left under Folders to migrate. The right side shows where the messages will go, and new folders carry a will be created mark. Leave Destination folder as it is to keep the import in a separate folder called Imported, with one subfolder per file.

Start the migration and open the log

Click Start migration. The screen counts Moved, Already in the mailbox and Errors while it runs. When you see Migration complete, click Open migration log to read the report.

Every email keeps its original date

Move email by hand and it often comes out stamped with the day of the import. Email Migration Tool for Gmail and Office 365 sends each one with its original date, so an invoice from 2019 still sorts under 2019. We measured it on a live Gmail, and the dates matched to the second.

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Start a big job and get on with your day

A long import rarely finishes in one sitting, because the Wi-Fi drops at some point or you need the machine back long before the last message has gone through. The program expects that. When the line drops it reconnects by itself, up to 5 attempts in a row, with waits from 2 to 30 seconds. Before you begin, the screen gives an estimated duration, and we do not promise a speed.

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Start a big job and get on with your day.

Email travels straight from your PC

There is no relay of ours in the middle. The program reads what is on your disk and talks with Gmail or Office 365 directly. Passwords are not saved. The Microsoft token lives in memory, so the next launch sends you to Microsoft again.

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Recognizes a format by its content

Email Migration Tool for Gmail and Office 365 checks the first bytes and ignores the extension. A Thunderbird file with no extension is treated as MBOX. You can add several files at once. To import EML messages, add the folder that holds them.

Five destination presets

The list has Gmail, Microsoft 365 / Outlook.com, Yahoo Mail, iCloud Mail and Other IMAP server. For a server of your own, fill in IMAP server, Port and Security. The defaults are port 993 and SSL/TLS. STARTTLS is there too.

Picks up where it stopped

A journal records every email that was delivered. Shut the lid or cut the power, and the next run begins where the previous one ended. We killed the process on purpose, 4 kills in a 130-email run on our own test IMAP server, and found zero extra copies.

You decide what lands where

Deleted Items and Junk Email begin unticked, and so do Trash and Spam. Period narrows the job to the last 12 months or to your own range. Nested folders are recreated parent first. Tick Merge into the mailbox folders and Sent Items is mapped to the Sent folder of the mailbox.

A plain-text report at the end

The final screen lists Moved, Already there and, if any, Errors for every folder. The Open migration log link leads to a text report with its own columns per folder, such as existed and too big. A message bigger than the server allows is skipped, and the reason is written down. A damaged PST does not block the others.

20 interface languages

Pick any of 20 languages in the Language menu, German and Japanese among them. The program runs on 64-bit Windows 10 and 11. No need to install .NET, and it works under ordinary user rights.

Moments when a mail file needs a mailbox

A new laptop next to an old desktop computer.

A new PC without Outlook

The old computer kept years of email in one PST. The new one has a browser. Carry the PST across and import it once.

An address with a closing date

A provider or an employer switches it off on a set day. Export what you have while you still can. Import it later into the Gmail you keep.

A USB drive passed from one hand to another.

A PST handed over by a colleague

Someone left the team and their correspondence reached you as one huge PST. Import the two folders that matter and leave the rest in place.

A graduation cap on a desk next to a laptop.

A Takeout download from a college address

Student logins expire. Takeout hands you an MBOX that webmail has no use for. Import it into personal Gmail and search it there like any other mail.

Who needs Email Migration Tool

People moving from Outlook to Gmail

You check email on the web now, and a decade of Outlook history sits unused. You want it searchable next to this week's messages. A Gmail migration tool for one person should not come with an admin console.

Small-office admins

You look after a handful of Microsoft 365 mailboxes, and every employee has a PST from the previous setup. A PST migration tool that works at the desk is enough. You sit down at each one, sign that person in and import their PST. And when Office 365 needs approval from IT, that is you.

Thunderbird and Google Takeout users

Your email lives in a Thunderbird profile or a Takeout archive, and Gmail will not take either one. Here you import emails to Gmail without setting up a desktop client first.

Source files the program reads

Three formats go in. The table shows where each one usually comes from and what reaches the mailbox.

Format	Where it comes from	What is read	What is carried over
PST	Outlook data file, exported from Outlook	Mail folders. Contacts, calendar items and notes are left out.	Folder tree and dates. Attachments with inline pictures. Read and draft status. Flags and categories are not carried.
MBOX	Thunderbird or Apple Mail. Google Takeout. Any plain MBOX file.	A single file. Thunderbird files with .sbd directories. An Apple Mail .mbox package. A Takeout file, where each message goes to the folder of its first user label and the other labels are not recreated.	Messages as they are, with their dates. Read and replied marks, stars and draft status.
EML	Single messages saved from a mail client	A folder of .EML files with its subfolders.	Messages as they are, with their dates. They arrive as read, because an EML file does not store a status.

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What to know before you start

Mail services set rules of their own. Here is how the program works with each of them.

The daily limit is counted for you

Gmail accepts about 500 MB a day over IMAP. The program counts what went out today and pauses before the limit. It is set to continue on its own after midnight, provided its window stays open. If you close it, press Resume next time, add the same PST and connect once more. A 10 GB PST takes about 20 days. No tool gets around that limit.

about 500 MB a day

An app password lets you in

Gmail keeps third-party apps out if they come with your regular password, and this version has no Google sign-in button. You create an app password in your Google settings, which requires 2-Step Verification. On a work, school or other organization account, Google may not offer app passwords, and then this version cannot connect.

Imported email sits under its own label

By default the import is filed under Imported plus the PST name. In Gmail that is a label, and nothing appears in your Inbox. Switch the Merge option on and the Inbox of the PST ends up in your Inbox. Deleting the label deletes nothing, and the messages stay in All Mail.

You sign in on Microsoft's page

Sign in with Microsoft opens the Microsoft page in your browser, and the program does not see the password. The consent screen there shows the name Outlook Mail Merge. That is our own registration, the one this sign-in runs through, so the name is expected.

A ready note for your administrator

A work or school tenant may require approval from its administrator, and IMAP has to be allowed. The What to show them link names the permission, and Copy for the administrator copies the wording. Policies differ. Try the sign-in with the free trial before you plan a big move.

Export a PST and you are ready

The program takes PST. OST and a live Outlook profile are not read. If your email is still inside Outlook, export it there: File, Open & Export, Import/Export, Outlook Data File (.pst). Quit Outlook before the run, because it locks the PST.

PST emails are rebuilt with all their parts

A PST does not store a message the way it arrived, so the program builds each one again. Subject, sender and recipients are there, with the date, the body in plain and HTML form, and the attachments. It is not a byte for byte duplicate. MBOX and EML go in as they are.

What you get	Free trial	Full version
Messages moved from each folder	25 newest	All
PST, MBOX and EML sources	✓	✓
All five destination presets	✓	✓
Resume without duplicates	✓	✓
Migration log	✓	✓
Trial uploads are real and stay in your mailbox. After you enter a key, click Move the rest and the program skips them.	Download	Buy now From $ 24.99

Email Migration Tool for Gmail and Office 365 - Import PST, MBOX and EML

Price

from $ 24.99 / month

Version

3.3

File Size

67.7 Mb

Last updated on

14/08/26

The free trial moves the 25 newest messages from each folder. No time limit.

System Requirements

Windows 11/10/8.1/8/7 (32/64 bit)
Intel i3, AMD Ryzen 5 or above
4 GB of RAM or above
NVIDIA® GeForce® series 8 and 8M, Intel® HD Graphics 2000, Quadro FX 4800, Quadro FX 5600, AMD Radeon™ R600, Mobility Radeon™ HD 4330, Mobility FirePro™ series, Radeon™ R5 M230 or higher graphics card with up-to-date drivers
1280 × 768 screen resolution, 32-bit color
1 GB of free hard disk space or above

Frequently Asked Questions

Can I import a PST file into Gmail?

Yes. Gmail itself has no upload button for a PST. To import PST to Gmail, add the file in the program, pick Gmail and sign in with a Google app password, not your usual one. The folders of the file become labels. A large file takes several days because of the Gmail daily limit.

How do I import a PST file into Office 365?

Add the PST, pick Microsoft 365 / Outlook.com and click Sign in with Microsoft. You import PST to Office 365 from a single PC, over IMAP and under your own Microsoft sign-in. Each run fills one mailbox. A work or school account may need an approval from the administrator first.

Does Microsoft have a migration tool?

Yes, for organizations. With network upload an administrator can upload PST to Office 365 in bulk. It takes a role that no group has by default, and Microsoft recommends PST files no larger than 20 GB. If you are one person with one file, a desktop Office 365 migration tool that works from your own sign-in is less work.

How do I transfer my Thunderbird emails to Gmail?

For a Thunderbird to Gmail move, open your Thunderbird profile folder and add the mail files from it. The program rebuilds the folder tree in Gmail as labels, and stars come along. Messages you deleted in Thunderbird are skipped, even when they are still inside a file that was never compacted.

How do I import an MBOX file?

Click Add files and select it, then choose the mailbox. An MBOX from Thunderbird or from Google Takeout is added the same way. An Apple Mail .mbox arrives on Windows as a folder, so add it with Add folder. To import MBOX to Gmail, the sign-in is the same as for a PST. To import EML to Gmail, add the folder of messages with the same button.

How do I import a PST file into my IMAP account?

Pick Other IMAP server, enter the server name and sign in with the user name and password of that mailbox. Use Test to check the connection before the run. On an ordinary IMAP server everything lands in one folder that you can delete in one go, so a trial run is easy to clean up.

Will importing the same PST twice create duplicates?

No. Messages that are already in the destination folder are not copied again. The program compares the Message-ID, and for a message without one it compares the date and the sender, then the subject and the size. Gmail adds a rule of its own. It keeps a single message per Message-ID and merges identical messages, so Gmail can show fewer messages than the report counts.

Do imported emails keep the date they were received?

Yes. For a PST the program uses the delivery time, and the sent or created time when there is none. For MBOX and EML it uses the date of the message, or the file time if the message has no date. People on the Microsoft Q&A forum describe the opposite after a manual import, where every message shows the day it was imported.

Is a 19 GB PST too big to import?

The program does not copy the whole file anywhere. It stages up to 50 messages or 64 MB at a time and removes them after the upload. It checks for 256 MB of free temp space before it starts. A big file costs time, and with Gmail 19 GB means more than a month. Run the trial on your own file first.

What does the free trial move?

The 25 newest messages from each folder of each file. Changing the period filter does not get around that number. After you enter a license key, run the migration again and the remaining messages are added without duplicates.

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Free import routes and where this program fits

The standard routes