How to export email as EML from any client

Which client gives you what

The single most useful fact in email collection: different clients export different formats from the same mailbox.

If your firm runs classic Outlook, you do not need to change anything about how the firm works. Open the mailbox in a browser for the duration of the export.

Outlook

Outlook on the web, and the new Outlook for Windows. Open an individual message, open the overflow menu on the message toolbar, and choose Download. The browser saves a .eml. The wording moves between builds — look for Download or Save as — and note that it applies to the message you have open, not to the conversation.

Classic Outlook for Windows. No .eml export. Dragging messages to a Windows folder saves .msg, as does File then Save As. Your options are to open the same mailbox in a browser and download from there, or to convert the .msg files locally — see converting MSG files.

A whole Outlook folder. Outlook’s own export produces a .pst archive rather than individual messages, which is a different problem covered in PST to PDF.

Gmail

Open the message, open the overflow menu on that message rather than on the conversation, and choose Download message. You get a .eml containing the original as received.

Two Gmail-specific things worth knowing.

The download is per-message, not per-thread. For a conversation you expand it and download each message you intend to produce, which is also the right behaviour — each message is its own communication.

And a file “attached” from Google Drive is not an attachment. The message carries a link, not the file, so there is nothing to extract. If a Drive link matters, the document behind it has to be collected separately along with its revision history. Gmail to PDF for court covers this in more detail.

Apple Mail

Select the messages, then File, then Save As, and choose Raw Message Source as the format. That writes .eml. Selecting several messages and saving writes them out individually.

The default Save As format is Rich Text, which produces a formatted document rather than a message file and discards the headers. It is the wrong choice for collection and it is the default, so it is worth checking every time.

Thunderbird

Right-click a message and choose Save As to write a single .eml. Select multiple messages first to write them all out.

Thunderbird is also the pragmatic tool for the harder cases. It reads .mbox archives natively, including Google Takeout exports, so importing an archive and exporting the in-scope messages as .eml is the route that avoids uploading an entire mailbox to a web service. See MBOX to PDF.

Other webmail

Most webmail providers offer a per-message download that yields .eml, usually behind an overflow or “more actions” menu on the open message. Where a provider genuinely offers no download, the remaining options are connecting the account to a desktop client such as Thunderbird over IMAP and exporting from there, or using the provider’s data-export feature, which typically produces .mbox.

The one thing not to do

Do not collect by forwarding.

It is the fastest route, it is what people reach for under time pressure, and it produces a new message every time. The forward has your address in From, today’s date, a new Message-ID, and its own transport headers. The original message is inside the body as quoted text or as an attachment.

That is fine for getting a copy of something to read. It is poor practice for anything you intend to produce, and it is genuinely damaging if the message itself is contested — because the artifact you now hold is evidence that you forwarded something, not evidence of what the sender sent. Email metadata and admissibility covers what gets lost and why it matters.

Record what you did

Whichever route you take, write down who exported, from which mailbox, when, by what method, and against what scope. At small-matter scale this is a paragraph in a memo.

It costs a few minutes at the time and it is the difference between answering a question about collection method with a record and answering it with a recollection. Chain of custody covers what a record should contain.

Then convert once

With a folder of .eml files the rest is mechanical: batches of up to 100 through one conversion pass, a matter prefix on the filenames, sorted by the date on the message, and optionally combined into a single PDF for single-pass stamping.

Keep the .eml files afterwards. The PDF is the readable exhibit; the .eml is the native, and it is the only artifact that can answer a later question about headers, routing or attachment integrity.

Doing it in EML Exhibit

1. Work out which client will give you .eml

   Outlook on the web, the new Outlook for Windows, Gmail, Apple Mail and Thunderbird all export .eml directly. Classic Outlook for Windows gives .msg instead. The mailbox is the same either way, so the answer is often just to use a different client against the same mail.

2. Export whole threads, not individual hits

   Pull every message in a relevant thread rather than only the ones that matched a search. Producing selected messages out of a conversation invites the argument that context was removed.

3. Put everything in one folder per matter

   Keep the exported files together and away from anything else. This is also the moment to note where they came from and who pulled them.

4. Never forward to collect

   A forwarded message is a new message with new headers, a new date and a new Message-ID, with the original nested inside its body. Use it to read something, never to produce it.

5. Convert once you have the batch

   With a folder of .eml files, conversion to PDF or TIFF is a single pass with consistent pagination across the whole set.