How to Convert OST to EML Manually

If you are looking to convert OST to EML file format then you are at the right spot. We will discuss the complete manual process for the conversion. Many of the users want to switch from one email client to another email client but this is not an easy process. Microsoft Outlook’s OST saves multiple mailbox items i.e, contacts, emails, calendars, etc. while EML files save emails as dynamic file format. Thus, users want to migrate OST files to EML file format.

Before performing the conversion, first we will discuss in brief what is OST and what is EML?

OST files is a short form used for Offline Storage Table files and are created by MS Outlook. OST files store emails, calendars, tasks, data, contacts, etc. This format allows users to work even when the Internet connectivity is not available.

EML is an electronic mail which contains a single mail with attachment. Many email client applications allow EML files to store data such as Outlook Express, Thunderbird, Windows Live Mail, DreamMail, SeaMonkey, etc.

Now, what are the reasons to migrate OST to EML.

Reasons to Convert OST to EML

Many options are available for users to access their emails from any email client application. That’s the reason that users want to migrate emails from one email client to another one. But this is not the only reason, various other reasons are listed below.

Crash or System failure: When any virus attacks MS Exchange server then it leads to system failure and crash. These crashes are difficult to handle and generate errors in the Outlook profile. In such a scenario if the user is having backup of OST then it can be restored in such situations

Accidental Deletion of Data: If you have lost your data by deleting it accidentally from the Exchange server. Then, users can recover the lost data by converting the backed up or archived OST file to EML format to restore the deleted message.

Security Issue of Exchange Server: Live Exchange Server is not one of the most secure environments to work, but its features attract users to use it. If any security threat takes place then the data stored in the mailbox could be in danger. To overcome these security threats and secure your data, you can save a backup of the OST file that can help you to restore the lost data during a data crisis.

Migration of Data: If your company is changing its email platform from Outlook to Thunderbird, Windows Live Mail, DreamMail, SeaMonkey, etc then users can get easier access by converting OST to EML format to transfer data from one platform to the other.

These are some of the reasons for this conversion, now we will move forward with the Manual steps to migrate Outlook OST to EML.

Manual Steps to Convert OST to EML

There are three steps as listed below to export OST to EML file format -

Step 1: Drag and Drop

Users need to drag and drop the OST Data file that they want to transfer, into the configured Gmail account.

Step 2: Add Gmail Data into Thunderbird

After performing the above step, you need to add the same Gmail application data into the Thunderbird. Then, after the conversion process you can access the Gmail data in Thunderbird.

Step 3: Extract the EML Data from Thunderbird

Now, after the above steps. You need to extract EML files from Thunderbird by following the below process -

  • Select the emails that you transferred from Gmail to Thunderbird. You can select all by pressing Ctrl+A.
  • Right click on chosen emails and then select save as option.
  • The data will automatically be saved in EML format in Thunderbird.
  • Browse the location to save the resultant files. And the conversion of OST to EML format is successfully done.
  • Select the emails that you have transferred from Gmail to Thunderbird. Select all pressing Ctrl+A if required.
  • Right click on the selected emails, Choose Save selected message and then select EML format.
  • Browse to specify the location for resultant files and the process to convert OST to EML is now successfully done.

These are the Manual steps that you can follow to transfer OST files to EML file format. In case of bulk conversion of OST files to EML, then the process would become quite tedious and more time-consuming. You can use OST to PST Converter to overcome this difficulty. Also by using this software, you can easily convert all your OST files in various other file formats such as EML, MBOX, HTML, PST, etc. as well as to another email client application like Gmail, Yahoo.


We have discussed the reasons and the solution to convert OST to EML. To overcome the complexity in manual approach, you can opt for professional OST Converter software. You can go for any of the solutions that you feel is appropriate to your situation.

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