How to Convert PST Files to EML without Outlook?

PST and EML, what is the difference?

Worth a quick word, because it shapes everything else. A PST is Outlook’s mailbox container, one file that holds every folder and message together. An EML is the opposite idea, a single plain-text file for a single message, written in the standard mail format that almost every email program can open. That plain-text part is handy, an .eml opens in Thunderbird or Apple Mail, and you can even read one in a text editor like Notepad, which is why people who just want their mail as readable text reach for EML too. So converting means unpacking one PST into many .eml files, one per message.

“The trap here is assuming Outlook can just save EML, it cannot, dragging messages out gives you .msg, not .eml, and Thunderbird will not open a PST to help either. For a free route I point people at readpst from the libpst project, one command turns a PST into a tree of .eml files with the folders intact. It is command line, so for anyone who would rather not touch a terminal, a converter with a window and a preview does the same job. Both are legitimate, it just depends on your comfort with the shell.” Shubham Dixit, Data File Conversion reviewer (draft, pending approval)

Why Outlook will not just hand you EML?

You would expect Outlook to export EML, and this is where a lot of guides go wrong. Outlook does not save in .eml at all. If you drag messages out to a folder you get .msg files, Outlook’s own single-message format, not EML, and its export wizard only writes PST or CSV. Going the other way, Thunderbird reads EML happily but cannot open a PST to convert it. So there is no clean one-click inside either program, and the old trick of routing through Outlook Express does not count, that client was retired years ago. The real free path is a small dedicated tool, and there is a good one.

The free way, readpst

For a genuinely free and open-source route, readpst from the libpst project is the honest answer, and it is what the open-source searches are really after. It reads a .pst and writes every message as a separate .eml, keeping your folder tree. Install it with brew install libpst on a Mac, apt install pst-utils on Linux, or run it on Windows through WSL, then point it at your file.

The command is one line.

readpst -D -r -e -o output_folder your_file.pst

Here -e writes .eml files, -r rebuilds the folder structure, -o sets the output folder, and -D includes deleted items. It is a terminal command rather than a window, so it suits people who are comfortable there. If that is not you, skip to the tool below, which does the same thing with a preview.

If the mail is on a live account

One more free option, if the PST is just an archive of an account that still works. Add that account to Thunderbird by IMAP, let it sync, then use the free ImportExportTools NG add-on to export any folder as EML, right-click the folder, choose export, and pick the EML option. No Outlook, no command line. This only helps when the mail still lives on a server, but when it does it is the easiest path of all.

A tool, without the command line

For a standalone PST when you would rather not open a terminal, a converter does the same work in a window. The PCDOTS PST Converter reads the .pst directly, without Outlook, previews the folders, and writes each message as an .eml keeping the folder layout, in bulk. It runs on Windows and has a free version that handles the first ten items per folder, enough to confirm it reads your file. It is the practical pick when readpst feels fiddly or the PST is large, the same result with a preview and no command to type.

Here are the tool steps with the screens.

Step 1. Install and run the software on Windows, then open the menu.

Step 2. Choose PST files and add your .pst.

Step 3. Open Export and choose EML as the format.

Step 4. Pick a destination folder and save.

To open the results, our free EML viewer shows them without a mail client, and to take them further see import EML into Thunderbird. If MBOX suits you better than EML, see convert PST to MBOX.

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The methods compared

Match the route to your setup and how much you are converting.

Frequently asked questions

Can Outlook export emails as EML?
No. Outlook drags out as .msg and its wizard writes PST or CSV, not EML. You use a converter, readpst, or a client that syncs the account.

Is there a free open-source PST to EML converter?
Yes. readpst from the libpst project writes each message as .eml with folders. Install it with brew or apt, or run it on Windows through WSL.

Can I convert a PST to EML without Outlook?
Yes. readpst and a dedicated PST converter both read the .pst directly, so Outlook does not need to be installed at all.

Can Thunderbird open a PST to make EML?
No, Thunderbird cannot read PST. It can export EML only once the mail is inside it, which works if you sync the live account by IMAP.

Is an EML file just plain text?
Yes. An .eml is a standard plain-text mail file, so it opens in any email client and even in a text editor, which is handy if you wanted PST as readable text.

Will attachments survive the conversion?
Yes. Attachments are encoded inside each message, so a proper PST to EML conversion carries them into the .eml files.

So which route is yours?

It comes down to where your mail is and how you like to work. Is it sitting on a live account? Then add it to Thunderbird and export EML with nothing to install. Happy in a terminal? Then readpst turns the whole PST into .eml files with one free command. Or is it a standalone file and you would rather see a window and a preview? That is exactly what the converter is for. Three honest routes, no Outlook required for any of them, so the only real question is which one matches you.