Folders and labels
All messages
No messages match this filter.
Select a message from the list to read it here.
Univik Online MBOX Viewer
100% private. Runs only on your device
The .mbs message files from an Opera 12 or Opera Mail store, opened a day at a time in the browser. No client, no upload.
Or pick it from your device. Messages open in this tab, on your own computer, phone or tablet. Your mailbox is never uploaded.
The browser dropped its built in mail client when version 15 moved to the Blink engine, and the standalone Opera Mail that followed was discontinued a few years later. Vivaldi, started by former staff, later built a mail client of its own. The messages are still on disk as .mbs files. This page opens them in your browser on your own machine and sends nothing to a server.
An .mbs file is a message in mbox form. Drop it in and the tool shows the sender, subject, body and attachments with no conversion.
You do not have to track down an old installer or a Windows XP machine. The files open on whatever you use today.
Opera files one message per .mbs in dated folders. Pick a day's folder and the tool lists every message in it, ready to flip through.
Keep a message as .eml for Thunderbird, Outlook or Apple Mail. Pull out an attachment that only ever lived in Opera.
Short answer: copy the .mbs files, or the whole store folder, out of the old profile onto whatever device you have and load this page on it. Opera itself is not required anywhere.
The store is usually under AppData in an Opera or Opera Mail folder. Open the .mbs files here in Edge, Chrome or Firefox on the same PC or a newer one.
Version 12 ran on the Mac too, with the mail folder under Library. Copy the store out and open the .mbs files in Safari or Chrome.
A Linux profile from version 12 keeps mail under the hidden .opera folder. Open the files in Firefox or Chromium without installing anything else.
Share a few .mbs files to the phone over a private link and read them here in the browser. Handy for checking one old message away from the PC.
Copy the day folders to Drive or a USB stick and pick them here in Chrome. ChromeOS never had a client for these files, so this fills the gap.
M2 spread a mailbox across thousands of small files and a set of index databases. The tool reads the message files and leaves the rest alone.
Each .mbs holds a single message with its From - line and headers. The tool opens it as a one message mailbox, so the list shows that message and the reader shows its body.
Files sit under store, then accountN, then year, month and day, named by number. Pick a day folder and every .mbs in it loads, with a selector in the top bar to move between them.
omailbase.dat, index.ini, the indexer and lexicon folders and the oprXXXX.tmp cache files are Opera's own bookkeeping. The tool ignores them when you pick a folder.
The Unread, Received, Sent and mailing list views were built from index.ini, not from separate mailboxes. On disk a message is filed by date only, so this tool shows messages by date too.
Attachments stored in the .mbs open from the Attachments tab. Messages downloaded in low bandwidth mode may hold headers only, and what you see is exactly what was saved.
Message-ID, Received and Date lines are shown unchanged in the Headers tab, which is where an old thread's routing can still be traced.
In Opera Mail use Help and then About Opera Mail to read the Mail Directory. Without the client, look under AppData for an Opera or Opera Mail folder that holds a mail folder with a store inside.
Inside store open accountN, then a year, a month and a day. Drag the .mbs files into the upload area, or point Select a folder at the day to load them all.
Switch between messages from the selector in the top bar, open the Headers or Attachments tab and save anything you need as .eml.
The forum moderators documented the layout. Help, then About, is the sure way to find the Mail Directory while the client still runs.
Opera 12 kept mail in AppData\Local\Opera\Opera\mail or the Roaming equivalent, and the standalone client in AppData\Local\Opera Mail\Opera Mail\mail or its Roaming twin. A USB install of Opera 12 keeps the profile next to the program.
store\accountN\YYYY\MM\DD\number.mbs is the mail. N matches the account number in accounts.ini. Drafts for every account sit in store\drafts.
omailbase.dat tracks each message and its state. index.ini defines the views, the indexer folder maps messages to views and threads and the lexicon folder powers search. signatureN.txt holds each account's signature. None of them contain mail.
If mail is not where you expect, operaprefs.ini may have a Mail Root Directory line under its Mail section pointing somewhere else. The whole mail folder travels together, so look for a folder with store, omailbase.dat and index.ini side by side.
Low bandwidth mode fetched headers only for POP and IMAP accounts until you chose Fetch complete message. Those .mbs files are small and hold no body, and nothing can restore what Opera never downloaded.
This online page reads Opera messages a day at a time with no install. To merge a whole account's store into one list, search inside every message and print, the free Univik MBOX Viewer for Windows is built for that.
| Feature | Online Opera Mail Viewer | MBOX Viewer for Windows |
|---|---|---|
| Install needed | None, opens in the browser | 15 MB Windows setup |
| Operating system | Windows, Mac, Linux, Chromebook, iOS, Android | Windows 7 to 11 |
| Files uploaded | Never, runs on your device | Never, runs on your PC |
| Opera store | One folder of .mbs files at a time | Whole store merged into one list |
| Search | Sender, subject, recipients | Message bodies too |
| Large stores | Read in pieces | No size limit |
| Browser print of the open message | Direct printing | |
| Price | Free | Free |
A single email message saved in mbox form. M2 wrote one .mbs per message and filed it by account and date inside the store folder. Because it is mbox underneath, this page opens it directly and shows the message with its attachments.
Yes. Neither client is available any more and neither is needed. Copy the .mbs files, or the store folder, to any computer or phone and open them on this page. Everything is read in the browser.
That was Opera's design. M2 had no folders on disk. It kept every message as a small file under its date and built Inbox, Sent, Unread and mailing list views from index files. So a day's worth of mail is a folder of .mbs files, which is why the tool loads a folder and lets you step through it.
With the client running, Help, then About Opera Mail, prints the Mail Directory. Otherwise look under AppData, in Local or Roaming, for an Opera or Opera Mail folder containing mail. Inside that is the store folder. A USB install of Opera 12 keeps it beside the program instead.
Opera's low bandwidth mode downloaded only the headers of POP and IMAP messages until you asked for the complete message. If that was never done, the body was never on your disk. The tool shows what the file contains, and nothing can recover the rest without the original server.
No. The .mbs files are read straight from your disk and nothing is transmitted. There is no server behind the page and no account to create. It keeps working offline, with the connection off.
Here you open a folder of .mbs files and step through them with the top bar selector, which suits a day or a month. Merging an entire store into a single sortable list, with search across every body, is what the Windows viewer linked above does.
Open a message here and save it as .eml. Thunderbird, Outlook and Apple Mail all open .eml files with attachments intact. For a whole store in one go, the Windows viewer handles bulk export.
Dig the .mbs files out of the old mail store and read them here. No Opera 12, no standalone client and no upload.
Choose an Opera .mbs file