How to Batch Export Exchange Mailbox to EML on Mac & Windows?

Exporting emails from on-premises or hosted Microsoft Exchange Server mailboxes to EML involves converting message data from MAPI to the standard MIME format defined by RFC 5322.

Note: There is no admin command or GUI option within Microsoft Exchange to directly export an entire mailbox to .eml files in bulk as the native export tools including the New-MailboxExportRequest cmdlet only converter Exchange mailbox PST containers.

Read Here: How to Save Exchange Online/Office 365 emails as EML files?

Why Export Exchange Server Mailboxes to EML Files?

An Exchange email exported to EML preserves its RFC 822/5322 message headers, MIME structure and boundaries, and attachments encoded in Base64 – making a suitable format in following situations:

• Admins backup all Exchange emails to EML before migrating to a Cloud Server.
• Additionally, saving Exchange emails in universally compatible EML files reduced platform dependence; majorly for offline access.
• EML files store individual messages saving Exchange to EML enables granular archiving & text searchability.

Export Exchange Mailbox to EML Files in 5 Simple Steps

1. Download the RecoveryTools Exchange to EML export tool on your Windows or Mac device.
2. Choose if you want to migrate Hosted Exchange or On-Premise Exchange Server. Enter your Exchange Mailbox credentials.
3. Select the Exchange Folders form which you want to save emails in EML.
4. Choose “EML” as the saving option.
5. Browse the saving destination on your computer and press “Backup”.

Suggestion: You can also configure your Exchange account in Thunderbird and use the free “ImportExport Tools NG” add-on to save them in EML in bulk for free without Outlook.

Method 3: Programmatic Way to Extract Exchange Mailbox Emails as EML (EWS)

Note: This method is for developers to automate migrations and require custom code to export Exchange messages to EML as they are better suited to run scripts & handle issues.

1. Sign in to the Exchange Server EWS endpoint with an account that has permission to open the mailbox. An administrator can configure EWS impersonation for other users’ mailboxes.
2. List messages in a folder using FindItems, page 100.
3. For each message, request the MimeContent property.
4. Write the bytes to a file with extension.eml.

 

using System;

using System.IO;

using Microsoft.Exchange.WebServices.Data;

class ExportInboxToEml

{

static void Main()

{

var service = new ExchangeService(ExchangeVersion.Exchange2013_SP1)

{

// Placeholder credentials. Use a secure credential method in a real script.

Credentials = new WebCredentials(“[email protected]”, “password”),

Url = new Uri(“https://mail.contoso.com/EWS/Exchange.asmx”)

};

string outputFolder = @”D:\export”;

Directory.CreateDirectory(outputFolder);

Folder inbox = Folder.Bind(service, WellKnownFolderName.Inbox);

var view = new ItemView(100)

{

PropertySet = new PropertySet(BasePropertySet.IdOnly)

};

int counter = 0;

FindItemsResults<Item> page;

do

{

// FindItem call to EWS: one page of item IDs

page = inbox.FindItems(view);

foreach (Item item in page.Items)

{

// GetItem call to EWS: the MIME stream for one message

var props = new PropertySet(

EmailMessageSchema.MimeContent,

EmailMessageSchema.InternetMessageId);

EmailMessage email = EmailMessage.Bind(service, item.Id, props);

// Name the file by Internet Message ID; fall back to a counter if it is missing

string name = string.IsNullOrEmpty(email.InternetMessageId)

? “message_” + (++counter)

: email.InternetMessageId;

// Remove characters Windows does not allow in file names, such as