Import and export mail
You can move old mail into Bulwark from files, and save your mail as files to keep or to open in another program. Everything runs in your browser: the files go straight between your computer and your mail server.
Import
Right-click the folder the mail should go into and choose Import mail…, or open Settings > Backup & reset and click Import… next to Import mail under Mail files. Then click Choose files… and pick one or more files:
| File | Where it comes from | What is kept |
|---|---|---|
.eml | One saved message from almost any mail program | The message, its date; read and flagged state if Thunderbird saved it |
.zip | A ZIP of .eml or .mbox files, such as Bulwark's own export | The messages and their folders |
.mbox | Thunderbird, Apple Mail, Google Takeout, mutt and most other programs | The date the message was sent, read, flagged and answered state, tags |
.pst, .ost | Outlook (File > Open & Export > Import/Export > Export to a file) | Folders, dates, read and flagged state, attachments and inline pictures |
Pick the folder under Import into. For an Outlook file or a ZIP with folders, Recreate the folders from the file builds the file's folders inside that folder. Choose Top level to put them next to your own folders: Inbox, Sent Items and Deleted Items then go into yours, and folders with a name you already have are used again.
Click Import. The dialog shows how far it got. Run in background hides it while you go on with your mail; a small chip in the corner shows the progress and opens the dialog again, and a message says when it is done. When it is done, the dialog lists what was imported, what was left out and why (for example contacts and calendar items from Outlook, or messages Thunderbird had deleted), and the messages that failed.
Cancel import stops it. What was imported stays. To go on later, even after closing the browser, import the same file into the same folder again: Bulwark offers to continue where the last import stopped. Messages already imported are skipped, and messages that failed are tried again.
Export
Right-click a folder and choose Export folder… to save that folder, or open Settings > Backup & reset and click Export… next to Export all mail under Mail files to save every folder of your account.
Pick a format:
- mbox file (a ZIP with one mbox file per folder for the whole account): Thunderbird, Apple Mail and most mail programs open it, and read, flagged and answered state and the arrival time come along. Bulwark imports it back as it was.
- ZIP of .eml files: one file per message, in folders like yours. Any mail program opens them, but read state and arrival time aren't stored in them: imported again, the messages come back read.
Where the file goes depends on the browser. Chrome and Edge ask where to save it first and write into it as the export runs, so even a very large mailbox works. Firefox and Safari 26 download the file when the export is done, and delete their own copy afterwards. Older Safari and other browsers keep the export in memory and stop at 200 MB; export folder by folder there.
The export can run in the background like the import, and Cancel export stops it and deletes the unfinished file.
If your organisation turned export off, the export entries aren't shown.
Good to know
- Outlook doesn't store messages as they arrived. Bulwark keeps the original headers of mail you received and builds the body again from the text, HTML and attachments; mail you sent is rebuilt completely. The messages look the same, but their signatures don't verify any more.
- Messages attached to Outlook messages can't be read and are left out, and so is a message with an attachment bigger than the server takes.
- Importing the same file again after its import finished, or into another folder, gives you a second copy of each message.
- A folder of a shared mailbox imports and exports in that mailbox. Export all mail saves your own mailbox only.