Convert MBOX mailboxes from Thunderbird and other clients into a single Outlook PST file. No second email client needed.
Open the app and point it at one or more .mbox files. Thunderbird keeps each folder as a separate file inside its Mail folder, usually with no extension at all, so add every folder you want to bring over.
Leave the merge option off for one PST per mailbox, or switch on Merge into one PST to combine them. When merging, each source file becomes its own top-level folder, so folders with the same name never collide.
Set a destination on your drive and start. Outlook does not need to be open, or even installed, for this step.
In Outlook, go to File, Open and Export, Open Outlook Data File, and pick the new .pst. Your folder tree is there, with dates, read state and attachments intact.
Client switches go wrong when half the mail arrives and the rest goes missing. This tool is built so none of that happens.
SoftOrbits MBOX to PST Converter writes a valid Unicode .pst, and we tested the output in Outlook 2016. It is a genuine Outlook data file, not a lookalike that barely opens.
Subject lines, HTML and plain-text bodies, From, To and Cc, sent and received dates, the read or unread flag, and file attachments all carry over byte for byte.
The converter takes several .mbox files in one run. It can merge them into a single PST, where each mailbox lands in its own top folder, or write a separate PST per file. A single checkbox decides.
MBOX (RFC 4155) packs every message into one text file, split by From lines. Thunderbird writes the mboxrd style, and the converter reads that stream to rebuild the separate messages back out of it.
You have decided Outlook is your mail client now, often as part of a move onto a Windows setup, and you want years of Thunderbird mail carried over instead of starting from empty inbox.
A small business folding staff mailboxes into Outlook can hand each person's exported mbox to the tool and get back PST files, ready to attach to profile.
Someone leaves you a stack of mailboxes, some from Eudora, others off an old Unix box running Pine, and you just need them readable in Outlook without finding the original program first.
Plenty of programs write mbox, and they do not all name the file the same way. These are the sources the converter opens:
MBOX to PST Converter Software for Outlook
9 Mb
1.0
08/04/26