PST to EML — unpack an Outlook mailbox into messages
Turn a .pst mailbox into ordinary .eml files, downloaded as one zip. No message limit and no Outlook needed.
About this conversion
A .pst is a container, and sooner or later the messages have to come out of it. As .eml each message becomes its own file in the standard every mail program reads, so the archive can be moved into Thunderbird, kept in a folder on a drive, or handed over message by message without the original mailbox file following it around.
What is inside the zip
One .eml file per message, named by date and subject so they sort in order:
messages.zip 2021-05-03 Invoice 1042.eml 2021-05-03 Re_ Invoice 1042.eml 2021-05-07 Holiday rota.eml undated no-subject.eml
Opening the messages afterwards
Double-click an .eml and it opens as an ordinary message, attachments included, in Outlook, Apple Mail, Thunderbird or Windows Mail. To bring them into Outlook, select the files and drag them onto an Outlook folder; Thunderbird imports a whole folder of them with the free ImportExportTools NG add-on.
Every message sits at the top level of the zip — the folders of the .pst are not recreated, so the date at the start of each name is what keeps them in order.
Why .eml and not one big file
Separate files are easiest to hand over one by one, to attach to a ticket or a case file, or to keep in an ordinary folder on a drive where any search tool finds them. For moving a whole mailbox into Thunderbird or Apple Mail in one go, mbox is the quicker choice.
Just want to look inside it?
The same tool without converting anything: open a .pst file and read it.
You are not locked into EML
The file is parsed once and stays open, so the format is picked at the end rather than the beginning: the same .pst can leave here as CSV, XLSX, ZIP, MBOX, PDF, HTML, TXT or JSON. Before that you can search it by subject or address, filter by year, sender and attachment type, mark the duplicates and look through the archive overview.
Questions
- Are attachments kept?
- Yes. Each .eml holds its message with the attachments embedded, the way mail normally travels.
- Can I export only part of it?
- Yes. Search or filter first — the export contains exactly the messages you can see.