Compare
EML vs MBOX
EML commonly stores one email message. MBOX groups multiple messages in a mailbox file. Choose by the unit you need to preserve or move.
Which format should you choose?
Use EML for handing off individual messages; consider MBOX for mailbox-level migration or archiving.
Good fit for EML
Save or share one email message
- Keeping message headers, body, and attachments together
Good fit for MBOX
Archive or migrate collections of emails
- Exporting a mailbox as one file
Basic information
| Field | EML | MBOX |
|---|---|---|
| Extension | .eml | .mbox, .mbx |
| MIME type | message/rfc822 | application/mbox |
| Common uses | Save or share one email message | Archive or migrate collections of emails |
| How to open | Use a trusted mail client or viewer. Check the sender and attachment origin before opening attachments. | Import with an MBOX-compatible mail client or migration tool. Back up the source mailbox first. |
| Export or convert | When saving as PDF or another format, check that needed headers, body, dates, and attachments remain accessible. | After migrating or extracting EML files, compare message counts, dates, attachments, character display, and folder structure. |
Choose by use case
Keeping message headers, body, and attachments together
Save or share one email message
EMLExporting a mailbox as one file
Archive or migrate collections of emails
MBOXKey point 1
EML represents one email message.
More on the differencesKey point 2
MBOX can hold many messages in one mailbox file.
More on the differencesMore on the differences
Before and after migration, check message counts, attachments, dates, and folder organization in the target mail application.
- EML suits selecting or sharing individual messages.
- MBOX suits bulk mailbox export but folder mapping may need separate handling.
- Import support varies by mail application.
Frequently asked questions
Will one MBOX file preserve all folders?
Not necessarily. Verify how the export and import tools represent folder structure.