Everything you need to read a mail file. Nothing you don't.
No accounts, no sync, no inbox. Peek Mail does one thing: show you what's inside an exported email, beautifully and safely.
.eml and Outlook .msg
Opens both formats natively, including HTML mails with inline images, plain text, and attached emails. Large files open in the background.
Quick Look in Finder NEW
Press Space on a mail file in Finder and see the whole message, without opening any app.
winmail.dat unpacked NEW
Mails from Outlook or Exchange that hide their content in winmail.dat show their real body and attachments.
Find, print, export NEW
Search inside the message with ⌘F, print it, or save it as a PDF, header and attachments list included.
History sidebar
Every mail you open is kept with sender, subject and date, and it's searchable. Opening the same file again jumps back to its entry.
Clickable addresses
Click any sender or recipient to reveal the real address, copy it, or start a new email.
Attachments
See every attachment with its icon and size. Open it with a click or save it anywhere.
Headers & source
Inspect every header and the raw source with syntax highlighting and search. Made for debugging deliverability.
Updates, if you want
Peek Mail asks once whether to check for updates, and new versions install with a click.
Find what you're looking for. Keep what matters.
Press ⌘F to search the message itself, with a match counter and jumps between results. Print with ⌘P or save a PDF with ⇧⌘E: the sender, recipients, date and attachment list come along, so the copy makes sense on its own.
Peek without opening.
Select a mail file in Finder and press Space. The preview shows the whole message: sender, recipients, date, attachments and the formatted body.
- Outlook .msg files finally get a real preview on the Mac
- Offline by design: previews run sandboxed without network access, so tracking pixels never load
- Works with winmail.dat and every other format Peek Mail can open
For .eml files, macOS uses Apple Mail's preview by default. To use Peek Mail's, turn off Mail under System Settings → General → Login Items & Extensions → Quick Look.
See what really happened to a mail.
Switch to Headers or Source to check SPF, DKIM and DMARC results, follow the Received chain, or find exactly where a MIME part breaks.
- Highlighted authentication results: pass in green, fail in red
- Decoded values for
=?utf-8?B?…?=encoded headers - Search with match navigation and ⌘F
- MIME boundaries stand out, base64 payloads fade into the background
Your mail stays on your Mac.
Exported emails often contain things that matter, and sometimes things that bite. Peek Mail is built to show them without leaking or running anything. The only connection it makes on its own is an optional daily update check, and it asks you first.
Remote images blocked
Tracking pixels, remote images, stylesheets and fonts don't load until you click Load Images for that message. Quick Look previews never load them at all.
Mails can't do anything
JavaScript is disabled, and mails can't navigate, submit forms, or open local files and apps. Only web and email links open, in your browser or mail app.
Careful with attachments
Opened attachments are marked as downloaded so Gatekeeper checks them, and programs or scripts ask before they open.
Get Peek Mail.
A universal app for Apple Silicon and Intel Macs, signed with a Developer ID and notarized by Apple. Requires macOS 14 Sonoma or later.
Download
Get PeekMail.dmg from the latest release on GitHub.
Install
Open the disk image and drag Peek Mail into your Applications folder.
Open a mail
Drop an .eml or .msg file on the window, use Open With → Peek Mail, or press Space in Finder.
Tip: to make Peek Mail the default for .eml, right-click an email file → Get Info → Open with: Peek Mail → Change All…
Prefer to build it yourself?
All you need is Xcode 16 or later. The only third-party dependency, Sparkle for updates, is fetched automatically.
# Clone, build and install to /Applications
git clone https://github.com/jappi00/peek-mail.git
cd peek-mail
./build.sh --install
Peek into your mail files.
Free, open source, and made for macOS.