PST, MBOX, EML, MSG, EMLX, OST, OLM — 7 formats, 30 conversion paths. Upload, convert, download. Enterprise-grade privacy on European servers.
Trusted by IT teams, legal departments, and email administrators across Europe.
100 MB free credit · No credit card · No subscription
MailtoPst is the only email file converter that runs entirely in the cloud. While every other tool requires you to download and install desktop software, MailtoPst works from any browser on any device — Mac, Windows, Linux, or Chromebook.
Desktop converters
MailtoPst
Simple & fast
No software to install. No account setup required for your first conversion.
Drag & drop your email file — MBOX, EML, MSG, EMLX, OST, OLM, or PST. Files up to 50 GB.
Choose your target format. Our cloud engine converts instantly — metadata, folders, attachments preserved.
Your converted file is ready. Download it directly or receive it by email.
Universal compatibility
Whether you're migrating from Thunderbird to Outlook, archiving Apple Mail, or recovering orphaned Exchange files — MailtoPst handles every major email format with binary-level precision. No generic wrappers. No data loss.
Conversion technology
Most online converters rely on generic, open-source processing that strips your metadata and corrupts folder structures. MailtoPst is different. We designed a proprietary conversion engine from the ground up, purpose-built to understand the internal architecture of every email format we support.
Every format is parsed at the binary level. No generic wrappers, no shortcuts. Your data is read the way the format was designed to be read.
Folder hierarchies, nested attachments, read flags, timestamps — our engine maps the internal structure of your source file directly into the target format. Nothing is lost in translation.
We optimized for accuracy first. Headers, character encodings, embedded images, calendar items — every detail transfers intact.
Email formats evolve. Our engine is continuously updated against official format specifications to handle edge cases, legacy files, and corrupted archives.
Source file
Conversion Engine
Proprietary · Binary-level
Converted file
100% fidelity · Ready to download
Your data is protected
End-to-end encrypted
Privacy first
We built MailtoPst with privacy as the foundation, not an afterthought. Your files are processed on European servers and automatically deleted. We never read, analyze, or store your data.
Full regulatory compliance, no exceptions.
No analytics scripts, no third-party trackers on your data.
Your files are purged automatically, or delete them instantly yourself.
Military-grade encryption for every file transfer.
Use cases
Whether you're migrating thousands of mailboxes or recovering a single archive, MailtoPst handles the workload.
Moving your organization from one email platform to another? Convert entire mailbox archives without data loss or downtime.
eDiscovery, litigation holds, regulatory audits — convert email archives into the format your legal team needs, with full metadata preservation.
Consolidate years of email from multiple clients and platforms into a single, searchable format. Perfect for long-term retention.
Lost access to an old email client? Recover your emails from orphaned PST, OST, or MBOX files and convert them to any format you can open today.
Built for real workloads
Cloud-powered conversion with no file size limit worries. Works from any browser, any OS.
Resumable uploads — if your connection drops, pick up where you left off. No file size anxiety.
Folder hierarchy, attachments, read status, timestamps, flags — all metadata intact.
Mac, Windows, Linux, Chromebook — if you have a browser, you can convert.
Our servers do the heavy lifting. No CPU drain, no storage needs on your machine.
ZIP hundreds of files together. Directory structure becomes folder hierarchy in the output.
Most files under 1 GB convert in under a minute. Download immediately or get an email link.
30
conversion paths
7
email formats
50 GB
max file size
< 60s
average conversion
30 conversion paths between 7 email formats. Here are the most common.
Under the hood
Unlike generic tools, MailtoPst processes each format at the binary level — preserving every metadata field, folder hierarchy, and attachment with cryptographic integrity checks.
Each format (PST, MBOX, OLM, EML…) is parsed at the binary level following official Microsoft/Apple specifications. No generic libraries, no shortcuts.
PST, OST, MBOX, EML, EMLX, MSG, OLM — convert freely between any combination, in both directions. Full bi-directional support.
Folder hierarchy, read/unread flags, timestamps, headers, MIME attachments — everything is preserved with cryptographic integrity checks.
The engine streams data through a pipeline without loading entire files into memory. Convert 50 GB archives without out-of-memory errors.
TLS 1.3 in transit, AES-256 at rest on European servers. Files auto-deleted after 24h. Zero logging of email content.
Resumable uploads via TUS protocol. A dropped connection picks up exactly where it left off, even for massive archives.
100 MB free credit · No subscription
FAQ
MailtoPst supports 7 formats: PST, MBOX, EML, MSG, EMLX, OST, and OLM. You can convert between any supported combination — that's 30 conversion paths.
Every account starts with 100 MB of free credit — no credit card required. Need more? Buy credit from €39.99/GB, with volume discounts up to -20% for large files. Failed conversions are never charged.
All files are processed on European servers. They are automatically deleted after 24 hours — and you can delete them instantly at any time. They are never read, analyzed, or shared.
MailtoPst supports files up to 50 GB per upload, with resumable upload technology — if your connection drops, you can pick up where you left off.
Yes, fully. MailtoPst is GDPR, ePrivacy, and CCPA compliant. End-to-end TLS 1.3 encryption, zero cookies, zero tracking, automatic 24h deletion.
If a conversion fails for any reason, you are not charged. You only pay for successful conversions.
Free desktop converters typically use generic processing that often corrupts folder structures, strips metadata, or fails on large files. MailtoPst uses a proprietary conversion engine that processes each format at the binary level, preserving every detail — folders, attachments, read status, timestamps, and flags. Plus, it runs in the cloud, so there's nothing to install and no file size limit.
Absolutely. MailtoPst handles files up to 50 GB each, supports batch conversion via ZIP uploads, and preserves full folder hierarchies. IT teams use it to migrate between email platforms without data loss or the need for expensive enterprise migration software.
Our engine is built for fidelity. It preserves folder structure, attachments, read/unread status, flags, timestamps, and all standard email headers. If a conversion cannot complete perfectly, it fails rather than producing a corrupted output — and failed conversions are never charged.
First conversion free. No credit card required.