Open a PST file on a Mac

Outlook for Windows stores mail in .pst files, and Apple Mail can't open them. Moving to a Mac with old archives is one of the most common reasons people search for a “PST viewer for Mac”.

Updated 2026-10-26 · 5 min read

Option 1: browser viewer, nothing to install

Letterlark runs in Safari, Chrome or Firefox on macOS. Drop the .pst on the page, then browse and search. You can export messages to MBOX and import that into Apple Mail (File › Import Mailboxes), or save messages as PDF/EML.

Option 2: Outlook for Mac

With a Microsoft 365 subscription, Outlook for Mac can import a PST (File › Import). The mail is then added to your Outlook mailbox. Good if you want to keep using Outlook; overkill if you just need to look something up.

Option 3: readpst via Homebrew

Install Homebrew, then brew install libpst, then readpst -o ~/Desktop/pst-out ~/Downloads/archive.pst. You get MBOX files per folder that Apple Mail or Thunderbird can import. Free, but command line only, and attachments/encodings in some old archives come out imperfectly.

Moving PST mail into Apple Mail

Open the PST in Letterlark.
Select a folder's messages and export MBOX (one MBOX per selection/folder).
In Apple Mail: File › Import Mailboxes › Files in mbox format.

The free version exports 20 messages at a time; a $19 one-time license removes the limit.

Open your mail file now. Letterlark opens PST, OST, MSG, EML and MBOX files in Chrome, Edge, Firefox or Safari on Windows, Mac, Linux or Chromebook. Files are read on your computer – the app page cannot upload anything. Viewing and search are free without limit; exports (PDF, EML, MBOX, CSV, attachments) are free up to 20 messages at a time. A one-time license is $19 (Personal) or $49 (Pro, business use).

Open Letterlark – free

Questions and answers

Can Apple Mail open PST files?

No. Convert to MBOX first, then use File › Import Mailboxes.

Does it work on Apple silicon (M1–M4)?

Yes – a browser-based viewer doesn't care about the processor.

Sources and product names: Apple Mail help (Import mailboxes); Microsoft support for Outlook for Mac import; libpst documentation. Microsoft, Outlook, Gmail, Google Takeout, Apple Mail and Thunderbird are trademarks of their owners. Letterlark is independent and not affiliated with them.