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How to Convert OST to EML in Batch? Know Direct Techniques

  author
Published By Jamie Kaler 
Rollins Duke
Approved By Rollins Duke
Published On September 29th, 2026
Reading Time 5 Min Read

Are you trying to export OST file into EML format to access it in Thunderbird, SeaMonkey & other email clients? Then this blog is for you! In this updated article users get to know how to export individual Outlook emails into EML format without losing structure. EML file is very useful format that can be used outside Outlook without requiring configuration. In this blog, users learn simple method to convert OST to EML format with attachments. This article explains everything that you require during OST to EML export process. Let’s continue with us.

What are OST & EML? Why Convert OST to EML?

OST format used by Microsoft Outlook which store local offline copy of your mailbox data from Exchange Server. On other hand, EML format is single email file that saves your email with intact attachments & metadata. Many users choose EML over OST because it can be opened in multiple email clients without any configuration. Users can also open EML files without email client whenever they want with third-party solution. Let’s look at more reasons to export OST to EML.

  • If your Exchange account is deleted or deactivated, converting it from OST to EML helps users to recover orphan emails.
  • To open EML files, users do not need active Exchange or IMAP server to access emails.
  • Save OST as EML for long-term archiving. It saves data if your Outlook crashes or your profile gets corrupted.
  • Users can easily share EML files with anyone.
  • There is no dependency on specific Windows version, unlike OST files. Users can access EML files on cloud storage, external drives, & macOS.
  • Once OST is converted into EML, it also maintains original message properties.
  • EML files can also be accessed in audits, compliance checks, & eDiscovery.

How to Manually Convert OST Files into EML Format? (Free Tricks)

If you want to freely export OST to EML then you can use Mozilla Thunderbird which help users to export OST to EML. Check step-by-step guide below to convert OST files into EML format.

Method 1: Use Thunderbird & Outlook to Convert OST to EML

#Phase1: Export PST File from Outlook

  1. Open Microsoft Outlook.
    open outlook
  2. Tap File, then choose Open & Export option.
    open and export option
  3. Now go to Import/Export option.
  4. Pick Export to a file option.
    export to a file
  5. Tap Next, select Outlook Data File (.pst).
    outlook data file
  6. Choose mailbox you want to export as PST.
    select mailboxes
  7. Browse to location & save PST file on your computer.
    browse location and save pst file
  8. Click Finish.

#Phase2: Import PST File to Mozilla Thunderbird

  1. Download & open Mozilla Thunderbird.
  2. Click Tools menu option & select Import.
    menu option
  3. Now select Import from Outlook option.
    import option
  4. Choose Outlook PST file & import them in Thunderbird.
    import from outlook
  5. Check Imported PST files in Thunderbird.
    import pst to thunderbird

#Phase3: Export Thunderbird Emails as EML

  1. In Thunderbird, go to Add-ons & Themes.
  2. Install ImportExportTools NG extension in Thunderbird.
    install importexporttools ng
  3. Restart Thunderbird.
  4. Now go to imported PST file.
  5. Right-click, choose Export Message As.
  6. Choose EML Message Format (Messages Attachment Embedded).
    export thunderbird emails as eml format
  7. Check exported EML files.

Quick Tip: With the free method, users can export OST files into EML format. But users need to follow multiple steps to export OST files into EML. While exporting Thunderbird emails into EML, users can choose multiple EML features as per their requirements. Thunderbird allows users to save EML as index with attachments, etc. This method requires following multiple steps. Users also need to set up Thunderbird & Microsoft Outlook. If you have large Microsoft OST file, then choose professional method to export OST file into EML format.

Method 2: Use Gmail to Convert OST to EML

Users can use Gmail to export OST to EML. Thinking how? Check easy step-by-step guide to export OST as EML format.

  1. Open Outlook.
  2. Go to File options & Add account.
    add gmail account in outlook
  3. Enter Gmail address.
    enter gmail account
  4. Outlook opens new Window & sign in to your Gmail account.
  5. Once logged in, let Outlook sync emails.
  6. Open Gmail in web browser.
  7. Open email.
    open single email
  8. Tap on three dots.
  9. Download message as EML.
    download gmail email as eml format
  10. Repeat process again & again until you save all Gmail emails as EML.

Best Solution to Convert OST to EML in Batch

Download RecoveryTools OST File Converter Tool to convert OST files into EML format. This application directly exports OST files into EML format. This tool doesn’t require technical knowledge to operate. Both technical & non-technical users can use this application to save OST files in EML format. Install free demo edition of this application to learn more about the software.

Steps to Export OST to EML

  1. Download RecoveryTools OST to EML Converter Tool.
    download software
  2. Add the OST file using Select Files/Folders.
    add Outlook data file
  3. Choose only the desired OST folders.
    select required folders
  4. Select the EML format from the saving list.
    select eml as saving option
  5. Use filter to convert required OST file.
    use file naming option
  6. Click Convert to begin OST to EML conversion.
    start ost to eml conversion

Major Features of OST to EML Conversion Tool

The conversion tool offers various advantages to users. Some of the major benefits of converting OST to EML file format are:

  • Export OST emails from all default folders, including Inbox, Sent, Draft, Spam, Bin, and other created folders.
  • Select required OST file & remove duplicate OST files before starting conversion process.
  • This application also maintains folder structure during conversion.
  • Provides bulk conversion from OST to EML without any data size limitations.
  • With this automated solution, users can easily extract attachments from multiple OST files.
  • Does not require advanced technical knowledge to convert OST files into EML.
  • Works with every version of Windows as well as macOS versions.
  • Get free demo edition to check every features of this application without saving single dime.

In Nutshell

This blog provides simple techniques to convert OST to EML format. Users can choose free as well as professional methods to export OST files into EML format. If users worried about data structure during conversion then they can choose professional method which default select Outlook OST file. Users don’t need to follow multiple steps to export OST files into EML format. Choose any technique that provides safe conversion from OST to EML.

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