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Backup All Emails to MBOX With Attachments & Folder Structure

  author
Published By Karen Chard 
Rollins Duke
Approved By Rollins Duke
Published On July 21st, 2026
Reading Time 9 Min Read

Backing up emails in MBOX (a standard mailbox format), creates a local copy of bulk email messages in one single file for data retention, offline access via email client and compliance needs. In order to save emails to MBOX format the most reliable approach varies based on the email provider.

While limited email providers like Gmail offer a native tool, a free standard approach that works with all email services includes using a desktop email client like Thunderbird or Apple Mail. Additionally, there are external automated email to mbox export solutions especially for dealing with multiple larger mailboxes at once – especially where data integrity is crucial. Here we have covered the most suited methods for every email service.

Note: This guide is for all Gmail, Microsoft 365, Outlook.com, Yahoo Mail, Apple Mail, Thunderbird, and other IMAP-based email accounts users.

Table of Content Hide
  1. Why Backup Emails in MBOX Format?
  2. Choose the Right Backup Method
  3. Important Pointers Before Backup
  4. Method 1: Dedicated Backup Solution
  5. Method 2: Native Export Features
  6. Method 3: Desktop Email Clients
  7. After You Backup Emails
  8. FAQs

Why Backup Emails in MBOX Format?

IT administrators, or compliance & audit teams working with MSPs, large enterprises and personal users prefer downloading their emails in MBOX format specifically due to various advantages like easy-portability, wide-compatibility, and long-term reliability.

  • Complete Mailbox Storage: MBOX file allows you to save multiple email messages in a single file in a concatenated way with attachments, inline images & formatting preserved with Base 64 encoding. You can store multiple mailboxes like – Inbox, Sent, Drafts, Important etc. under a single file without any issue.
  • Long Term Storage Reliability: Emails stored in MBOX files are less prone to corruption as MBOX file is primarily a plain text format, even if some part of MBOX gets corrupted they can be easily recovered.
  • Easy to Access or Recover: Emails preserved as MBOX are compatible with multiple email clients on both Mac, Windows and Linux like Mozilla Thunderbird, Apple Mail, SeaMonkey, Claws Mail, Mutt which makes them versatile and easy to import in source account.

Hence for practical reasons like backing up emails before account deletion, compliance needs and personal backup before migration to another email service – MBOX can be an ideal choice.

How to Save Email Messages as MBOX? Choose the Right Way

The exact method one should choose depends not only on the email service provider but various other factors like – mailbox size, technical skills of the users, urgency and data integrity. Here is a quick comparison between multiple methods and who should choose it.

Factor Free-Native Tool Email Client (Apple Mail/Thunderbird) Automates Email to MBOX Tools
Supported Email Services Limited to Gmail and some other less renowned email services All IMAP and POP supported email accounts 200+ email services like Gmail, Outlook, Yahoo, or iCloud Mail, Zoho etc + IMAP
Folder Structure Preservation Yes Generally preserved but may vary based on email client Yes
Bulk Data Handling No imposed limit – however results files may get split 2GB-4GB practical limit – although no official documented limit No cap allotted by RecoveryTools Email to MBOX Converter
Time Taken Can take up to hours and several days Based on the mailbox export Slightly faster export than manual way due to API based connection for popular email services
Technical Skills Medium Medium – High Low
Best For Individual level single account export Free alternative if your email service does not offer in-built solution For batch backup of multiple email accounts at once

Important Pointers to Know When Backing Up Emails to MBOX Format

In order to avoid interruptions and ensure seamless email export to MBOX format keep these pointers in mind. They are of importance no matter what method you are choosing.

  • Your destination storage device and drive must have sufficient storage space to ensure mailbox export in MBOX format.
  • Downloading emails as MBOX files requires one to connect to the email server at all times hence require a stable internet connection.
  • Before you start to export your mail messages to MBOX format make sure you collect your verified credentials such as email address, App Password and even secondary device if you are 2FA or MFA enabled.

Method 1: Backup Emails to MBOX Format with Dedicated Solution

RecoveryTools Email Backup Software for Mac & Windows is an external automated solution to download emails from any email service such as – Outlook.com, Yahoo, Gmail, Microsoft 365, Zoho etc. in MBOX format with attachments and with fully preserved folder structure, email headers and email message properties. Best approach for businesses with multiple cloud or IMAP-based email accounts without effort, sharing your password to a third party and downtime.

Note: Free trial version of the tool is also available to backup 25 emails per folder to MBOX file before considering upgrading to the pro version.

Steps to Backup Emails to MBOX Using RecoveryTools Automated Tool

  1. Download and launch the Email to MBOX export tool.
    install software
  2. Select your email provider from the source panel.
    login mail
  3. Enter your credentials and sign-in using OAuth/Normal Password/App Password – based on the provider and authentication method enabled.

Note: Here you can also use batch mode to backup multiple email accounts to MBOX by importing a CSV holding credentials. The option is available as a small checkbox.

  1. Select the folders from which you need to download mail as MBOX files.
    select email folders to be saved as MBOX
  2. Use advanced filters to selectively choose emails based on date range, sender & receiver address.
  3. Choose MBOX as the saving type from drop down.
    mbox as saving type
  4. Browse the saving destination and click on the Backup button.
⚡ Advantages of RecoveryTools to Backup Emails in MBOX Format
🔌
Easy Standalone Direct Backup Without Configuration
⏰
Scheduled Backup Option for Automatic Email-to-MBOX Backup
🛡️
HIPAA, CCPA, and GDPR Compliant
🔒
Passwords and Data Are Never Stored or Transferred to External Servers
✅
100% Complete Preservation of All Email Attributes

Method 2: Backup Emails to MBOX Using Native Export Features or Tool

This method to save email as MBOX files using a native tool or feature is available for some email providers like – Gmail (via Google Takeout), Fastmail, and Runbox. It is not available for other email services – in such cases use a dedicated tool or go to method 3. Users also encounter other issues like lack of customisation feature and long export time using this method.

Using Google Takeout – Only for Gmail

  1. Go to https://takeout.google.com/.
  2. Sign in your Gmail account from which you want to preserve emails as MBOX files.
  3. Deselect all and only tick on the checkbox for Mail.
  4. Choose the following export settings:
    • Transfer to: Send download link via email
    • Frequency: Export once
    • File type & size: Zip and you can also split based on your needs.
  5. Click Create Export. Wait for the archive to be created and downloaded through the generated ZIP file received over mail.

Backup Fastmail emails to MBOX Format Natively

  1. Sign in to your Fastmail account via webmail.
  2. Go to Settings > Migration > Export.
  3. Select the New mail export option.
  4. Selectively choose the mailbox folder and even apply date range filters.
  5. Export and download the ZIP further extract the ZIP to get your emails saved in MBOX format.

Method 3: Download Mail as MBOX Files Using Desktop Email Clients

Using a desktop email client to create email backup in MBOX format is especially helpful with IMAP based email services or custom domain mailboxes where there is no native option. It is a free manual solution that can also prove to be easier if your email account is already configured in the desktop client. Here we have discussed 2 major email clients for your needs:

Note: You can only backup limited emails to MBOX format one account at a time making it ideal only for individual users.

Using Thunderbird Email Client on Windows/Linux/Mac

Prerequisite: You need to install the Thunderbird application beforehand on your computer and set up the email account from which you want to download emails as MBOX. Install ImportExport Tools NG to export Thunderbird emails as MBOX via Menu >> Themes & Add-Ons.

  1. Open Thunderbird and select the mailboxes from which you want to save emails as MBOX.
  2. Right-Click >> ImportExport Tools NG >> Folder Export (MBOX).
  3. Browse the saving location and press Save.

Note: Using the ImportExport Tools NG you can export at max 4GB emails as MBOX files at once.

Using Apple Mail Client on Mac Devices

With the Mac/Apple Mail application you can back up email messages in MBOX format up to 2 GB (real-world tested) from any configured account with the in-built option of the application.

  1. Go to the Mail app on your Mac.
  2. Go to Mail >> Add Account and connect your email account.
  3. Select the mailbox that you want to export.
  4. Click Mailbox >> Export Mailbox.
  5. Browse to the destination folder and click Choose.
  6. You will get your email saved in MBOX format on Mac devices.
After You Backup Emails to MBOX Format
  • Verify if all emails, attachments, and folder hierarchy have been backed up successfully.
  • Once you save your emails to MBOX format you can easily copy them to an external drive or NAS device or access them inside email clients like Mozilla Thunderbird, Apple Mail, SeaMonkey, and Claws Mail whenever required.
  • You can use a dedicated MBOX Viewer to open emails in MBOX files without any email client.
FAQ: Save Emails as MBOX Files

Q: Which email services can be backed up to MBOX?

Almost all emails from different providers can be backed up in the MBOX format. Some email service providers offer native solutions while some require an email client or dedicated email to MBOX export solutions like RecoveryTools.

Q: After backing up the email as MBOX, can I delete the email from the email account?

Yes, you can delete emails from the source after backing them up in MBOX format. Before you delete, make sure the MBOX file has all the mailbox data and can be opened in an email client.

Q: How much time does it take to backup 20GB of emails in MBOX format?

Time taken to download emails to MBOX varies widely based on the method used, internet speed, system compatibility, and server response speed. For 20GB it can take somewhere between 45 minutes to several days.

Q: Can I backup multiple email accounts to MBOX in one go?

Although it is possible to download emails from multiple accounts in MBOX format simultaneously, free-manual solutions cannot guarantee such results. For this, you will need a dedicated tool.

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