How to Import MBOX to Outlook Account
In short: To import MBOX to Outlook account, know that Outlook does not read MBOX, since it uses PST. The free route is to load the MBOX into Thunderbird with the ImportExportTools NG add-on, add a shared IMAP account like Gmail to both Thunderbird and Outlook, then drag the mail through it. The direct route is to convert the MBOX to PST with a tool, then import that PST into Outlook. New Outlook has no import, so use classic Outlook or a tool.
Why Outlook will not import an MBOX
This is the fact behind the whole problem. Outlook stores mail as PST and has no Import MBOX option, so it cannot open the file or bring it in. MBOX is the format used by Thunderbird, Apple Mail and a Google Takeout, which is why the file lands on your desk but Outlook ignores it. To get it in, you have to change the container. You either route the mail through a mailbox both Thunderbird and Outlook can reach, an IMAP account. Or convert the MBOX into a PST that Outlook imports natively. One more thing to know: only classic Outlook can import a PST, since New Outlook dropped the Import and Export wizard.
Senior Analyst, Corbett Software
“Outlook has no MBOX import, so people assume it is impossible. It is not, it just needs a bridge. If you like free and do not mind setup, go through Thunderbird and an IMAP account. If you want it done in one step, convert the MBOX to PST and import that into classic Outlook.”
Free: bridge it through Thunderbird and IMAP
This costs nothing and moves everything, using Thunderbird and any IMAP account such as Gmail as the go-between.
- Install Thunderbird, add the ImportExportTools NG add-on, then right-click a local folder and import your MBOX file.
- Add an IMAP account, for example a Gmail address with an app password, to Thunderbird.
- Drag the imported mail into a folder under that IMAP account, then wait for it to upload to the server.
- In classic Outlook, add the same IMAP account, then let it sync the mail down.
- To keep a local copy, export those folders to a PST with File, then Open & Export.
Convert the MBOX to PST, then import
To skip the setup, convert the MBOX to a PST and import it straight into Outlook.
The Corbett MBOX to PST Converter reads one or many MBOX files, with no Thunderbird needed, then writes a PST with folders and attachments kept. It can also send the mail straight to a Microsoft 365 or IMAP account, so a filter lets you convert only a date range or folder. A free demo edition lets you preview first and runs on every edition of Windows.
- Install and open the tool, click Open, choose Email Data Files, then MBOX, then select your file.
- Preview the folders, then click Export and choose PST.
- Save the PST, then in classic Outlook go to File, then Open & Export, then Open Outlook Data File to load it.
Which route to pick
Pick by your comfort with setup and how much mail there is.
- Comfortable with a bridge: the Thunderbird and IMAP route is free and moves everything, though it is slower and more fiddly.
- Want it quick and clean: convert to PST and import, which needs classic Outlook but no Thunderbird.
- On New Outlook: it has no import, so switch to classic Outlook for the PST. You can also send the mail to your account over IMAP instead.
Frequently asked questions
How do I import an MBOX to my Outlook account?
Outlook has no MBOX import. Either bridge the mail through Thunderbird and a shared IMAP account. Or convert the MBOX to PST and import that PST into classic Outlook.
Why is there no Import MBOX option in Outlook?
Because Outlook stores mail as PST and does not support MBOX. The two formats do not read each other, so you move the mail through IMAP or convert the MBOX to PST.
Can I import an MBOX to Outlook without Thunderbird?
Yes. Convert the MBOX to PST with a tool, then import the PST into classic Outlook. Only the free bridge route needs Thunderbird.
Does New Outlook import MBOX or PST?
New Outlook imports neither, since it dropped the Import and Export wizard. Use classic Outlook to import a PST. You can also send the mail to your account over IMAP.
Will folders and attachments be kept?
Yes. Both routes keep the folder structure and attachments. A converter preserves them in the PST, while IMAP carries them as the mail syncs.
Does this change my MBOX file?
No. Both routes only read the MBOX. The original file stays as it is, so the mail arrives in Outlook as a copy.