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Email Converter

Whether you are migrating from Outlook to Thunderbird, archiving emails for compliance, or preparing a PST file for e-discovery — GoConvertFile handles every email conversion while preserving attachments, metadata, and folder structure. No registration required.

Convert PST to MBOX Online - Free & Fast

Convert PST files to MBOX online for free. High-quality conversion with no registration required.

Email Converter

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.pst,.PST (max 100MB)

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About PST and MBOX

PST

PST (Personal Storage Table) is Microsoft Outlook's proprietary file format for storing emails, calendar events, contacts, and other Outlook data locally on disk. PST files are commonly used for email archiving, backup, and offline access to Exchange mailbox data.

MBOX

MBOX is a generic, platform-independent mailbox format that stores all email messages concatenated in a single file with standardized delimiters. Converting PST to MBOX enables cross-platform email migration and access through Thundermail, Apple Mail, and other open-source email clients.

Common Use Cases

  • Migrate Outlook email archives to Thunderbird or Apple Mail using MBOX format.
  • Convert corporate PST archives to MBOX for cross-platform email search and eDiscovery.
  • Transform PST backup files to MBOX for import into Linux-based email servers.
  • Export Outlook personal archives to MBOX for long-term email preservation in open formats.

Format Comparison

CompressionLossless → Lossless
TransparencySupported
Use CaseConvert from email archiving, outlook backup and migration to email migration, cross-platform email backup
File Size~1MB to 10GB after conversion

FAQs

Is converting PST to MBOX free?

Yes, GoConvertFile offers free conversion of PST to MBOX for files up to 100MB. No registration required.

How long does it take to convert PST to MBOX?

Most PST to MBOX conversions complete within seconds for standard-sized files. Larger files may take longer depending on the conversion complexity.

What is MBOX best used for?

MBOX is ideal for email migration, cross-platform email backup. MBOX - generic mailbox format for email storage and archiving

What file size should I expect after converting PST to MBOX?

File size after PST to MBOX conversion depends on the content complexity and quality settings. Both formats use similar compression approaches so sizes are comparable.

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All Email Format Conversions

Complete list of supported email format pairs

📬TO MBOX

📧PST
PST (Personal Storage Table) is Microsoft Outlook's proprietary file format for storing emails, calendar events, contacts, and other Outlook data locally on disk. PST files are commonly used for email archiving, backup, and offline access to Exchange mailbox data.
losslessConvert from email archiving, outlook backup and migration to email migration, cross-platform email backup
📝OFT
OFT files are Outlook-specific email templates containing pre-formatted layouts, styling, and placeholder fields. They are designed for use within Outlook and cannot be directly read by other email clients, limiting their utility in cross-platform environments.
losslessConvert from email templates, repeated message formatting to email migration, cross-platform email backup
🍎EMLX
EMLX is Apple Mail's per-message email format that stores each message as an individual file with macOS-specific metadata. While convenient for Apple Mail, the format is specific to the Apple ecosystem and cannot be directly used by other email clients.
losslessConvert from apple mail email backup, macos email archiving to email migration, cross-platform email backup
📧OST
OST files store cached Exchange mailbox data in a proprietary binary format tied to specific Outlook profiles and Exchange accounts. When users leave an organization or switch email platforms, the cached OST data becomes inaccessible without the original Exchange connection.
losslessConvert from exchange offline cache, outlook data recovery to email migration, cross-platform email backup

📝TO OFT

📧PST
PST (Personal Storage Table) is Microsoft Outlook's proprietary archive format, bundling years of emails, calendar entries, contacts, and attachments into a single local file. While PST is comprehensive, extracting individual email templates for reuse requires converting the data into a purpose-built template format.
losslessConvert from email archiving, outlook backup and migration to email templates, repeated message formatting
📬MBOX
MBOX is a concatenation-based mailbox format storing all messages as plain text in a single file, widely used by Unix systems and open-source email clients. While excellent for message storage, MBOX does not provide a mechanism for extracting and repurposing email designs as templates.
losslessConvert from email migration, cross-platform email backup to email templates, repeated message formatting
🍎EMLX
EMLX is Apple Mail's format for individual email messages, storing content and metadata in macOS-native files. When an Apple Mail message contains a well-designed layout worth reusing, converting it to an Outlook template format enables recurring use across the organization.
losslessConvert from apple mail email backup, macos email archiving to email templates, repeated message formatting
📧OST
OST is Outlook Offline Storage Table that caches Exchange mailbox content for disconnected operation. Within this cached data, well-crafted emails and standardized responses may be worth extracting and repurposing as reusable templates for consistent team communications.
losslessConvert from exchange offline cache, outlook data recovery to email templates, repeated message formatting

🍎TO EMLX

📧PST
PST is Microsoft Outlook's proprietary container format that stores all mailbox data — emails, contacts, calendars, and attachments — in a single binary file tied to the Outlook ecosystem. Converting PST data to an open format enables access outside the Microsoft world.
losslessConvert from email archiving, outlook backup and migration to apple mail email backup, macos email archiving
📬MBOX
MBOX stores all email messages concatenated in a single flat text file with minimal structure beyond delimiter lines. While portable, this monolithic approach makes individual message management, indexing, and macOS integration difficult compared to per-message file formats.
losslessConvert from email migration, cross-platform email backup to apple mail email backup, macos email archiving
📝OFT
OFT files are proprietary Outlook templates that store email layouts with embedded resources and placeholder fields, accessible only through Microsoft Outlook. Users working across platforms need a way to access this template content in the Apple ecosystem.
losslessConvert from email templates, repeated message formatting to apple mail email backup, macos email archiving
📧OST
OST files are Outlook's cached Exchange storage format, tied to Windows and the Outlook application. When users migrate to macOS and Apple Mail, their OST archives become inaccessible without specialized tools, requiring conversion to Apple's native email format.
losslessConvert from exchange offline cache, outlook data recovery to apple mail email backup, macos email archiving

📧TO OST

📧PST
PST files store Outlook data as a local archive file, typically used for backup, archival, and offline access to mailbox data outside an Exchange server environment. However, some Outlook workflows require data in the offline storage format used by Exchange cached mode.
losslessConvert from email archiving, outlook backup and migration to exchange offline cache, outlook data recovery
📬MBOX
MBOX is a platform-agnostic, text-based mailbox format used by Unix systems and open-source clients like Thunderbird. While universally readable, MBOX files cannot integrate with Outlook's cached Exchange mode, which requires data in the proprietary OST binary format.
losslessConvert from email migration, cross-platform email backup to exchange offline cache, outlook data recovery
📝OFT
OFT is an Outlook File Template, a single-purpose format for storing pre-formatted email designs. While OFT serves its purpose for template creation, it does not integrate with Outlook's mail storage and synchronization infrastructure.
losslessConvert from email templates, repeated message formatting to exchange offline cache, outlook data recovery
🍎EMLX
EMLX files are Apple Mail's per-message email format, deeply integrated with macOS but invisible to Outlook and Exchange environments. When migrating to an Exchange-based infrastructure, EMLX data needs conversion to Outlook's native storage format.
losslessConvert from apple mail email backup, macos email archiving to exchange offline cache, outlook data recovery

📧TO PST

📬MBOX
MBOX is a plain-text, platform-independent mailbox format that concatenates all email messages in a single file using standardized delimiters. While universally supported by open-source email clients, MBOX lacks the rich metadata, calendar, and contact storage that Outlook provides through PST.
losslessConvert from email migration, cross-platform email backup to email archiving, outlook backup and migration
📝OFT
OFT is an Outlook File Template designed for creating pre-formatted email messages with consistent styling, placeholders, and embedded resources. While useful for template management, OFT files are not designed for long-term email storage and lack the comprehensive organizational features of PST archives.
losslessConvert from email templates, repeated message formatting to email archiving, outlook backup and migration
🍎EMLX
EMLX is Apple Mail's native email format, storing individual messages as separate files with full metadata in the macOS ecosystem. While well-integrated with Apple Mail, EMLX files cannot be read by Outlook and are difficult to manage in Windows-based or Exchange environments.
losslessConvert from apple mail email backup, macos email archiving to email archiving, outlook backup and migration
📧OST
OST is Outlook Offline Storage Table, a cached copy of an Exchange mailbox that stores emails, calendar, and contacts locally for offline access. OST files are tied to specific Exchange accounts and cannot be opened independently, making them difficult to use for portable email archives.
losslessConvert from exchange offline cache, outlook data recovery to email archiving, outlook backup and migration

📄TO PDF

📧PST
PST (Personal Storage Table) is Microsoft Outlook's proprietary archive format for storing emails, calendar entries, contacts, attachments, and other mailbox data in a single local file. PST files are widely used for email backup, compliance archiving, and offline mailbox access.
losslessConvert from email archiving, outlook backup and migration to professional documents, reports, forms
📬MBOX
MBOX (MBOX mailboxes) - MBOX - generic mailbox format for email storage and archiving. Best for email migration, cross-platform email backup.
losslessConvert from email migration, cross-platform email backup to professional documents, reports, forms
📧OST
OST (Outlook OST archives) - Outlook OST - Offline Storage Table for cached mailbox data. Best for exchange offline cache, outlook data recovery.
losslessConvert from exchange offline cache, outlook data recovery to professional documents, reports, forms

Common Use Cases

Email Archiving

Convert emails from PST, EML, or MSG formats to MBOX or PDF for archiving and compliance. Preserve attachments and metadata.

Email Migration

Convert PST files from Outlook to MBOX for import into Thunderbird, Apple Mail, or Gmail. Migrate between email clients seamlessly.

Legal Discovery

Convert email collections to PST or PDF for legal discovery and e-discovery processes. Maintain chain of custody with metadata preservation.

Email Backup and Restore

Create portable backups of email folders in MBOX or EML format for disaster recovery and data portability.

Frequently Asked Questions

Pro Tips

Compress Before Export

Email archives can be very large. Compress PST or MBOX files before exporting to save bandwidth and storage space.

Check Email Limits

Some email clients have import size limits. Large PST files may need to be split before conversion to MBOX.