Mailcellar for Mac: Open Outlook PST, OST, MBOX and EML Files Without Outlook
by Kevin Fitzgerald
$29
Mailcellar opens old mail archives on your Mac without Outlook: Outlook PST files, offline OST files from classic Outlook, MBOX and EML files, and Apple Mail exports. Browse the folders, read every message, search years of mail in a moment, and export what you need. It only reads your archives and never changes them.
Open and read
PST files from Outlook 2003 and later (tested with Outlook 2003–2013-era Unicode PSTs), OST files from classic Outlook 2013 and later (tested with Outlook 2013 and Outlook.com OSTs), MBOX, single EML files and whole folders of them; older Outlook 97–2002 ANSI PSTs are supported through libpff
The folder tree with message counts, a fast message list (100,000 messages scroll and sort smoothly) and a reader with the HTML, rich text or plain text version
HTML mail shown safely: no scripts, and remote images stay blocked until you click Load Images
Attachments with Quick Look; attached and forwarded Outlook messages open too
Password-protected PSTs are recognized and ask for their password; a Text Encoding menu for garbled old ANSI files
Search
Sender, subject, message text and attachment names, between dates, in one folder or the whole archive
A local index built in the background while you read; it opens instantly the next time
Export
Selected messages, a folder or search results as EML files, one MBOX mailbox, a PDF or a CSV of the headers
PDFs put every message on its own page with its headers and page numbers; print a whole conversation in date order
Save one attachment, all of a message's, or all of a folder's at once
Free and Pro
Opening, browsing, reading and search are free with no limit, so you can check your file before you pay. Without a key, exports and attachment saving work 10 at a time; the license key removes the limit. $29 once, not $49 a year.
What you get
The app as a signed, Apple-notarized .dmg (download right after purchase)
A license key that works on up to 3 of your Macs; paste it into Mailcellar › Settings › Pro
Free updates from inside the app
Mailcellar reads Outlook files with libpff (LGPL-3.0-or-later, source at fitztoppicks.com/mac/mailcellar/source). Nothing in this license stops you from modifying libpff or reverse engineering Mailcellar to debug such changes.
Requirements and privacy
macOS 14 Sonoma or later, Apple silicon or Intel. Read only: no repair, no conversion to PST, no Exchange or IMAP. Your mail never leaves your Mac. The only network requests are the license check with Gumroad, update checks and, when you click Load Images, that message's pictures.
Support: fitztoppicks.com/mac/mailcellar