How to Use the MailtoPst Email Converter Tool

Getting Started With MailtoPst

MailtoPst is a browser-based email conversion tool that handles all major email formats — PST, OST, EML, MBOX, and MSG. There is nothing to install: you upload a file, the server converts it, and you download the result. This guide walks you through the entire process from start to finish.

Step 1: Choose Your Conversion

Visit mailtopst.com and select the conversion you need. The most common options include:

• PST to EML — extract individual email files from an Outlook archive.
• PST to MBOX — convert an Outlook archive for Thunderbird.
• EML to PST — combine individual emails into an Outlook archive.
• MBOX to PST — bring Thunderbird or Apple Mail archives into Outlook.
• OST to PST — convert Outlook’s offline cache to a portable archive.
• PST to MSG — extract Outlook-format individual messages.

If you are unsure which conversion to pick, see Convert email backup for a format identification guide.

Step 2: Upload Your File

Once you have selected the conversion type, upload your source file:

• Drag and drop the file directly onto the upload area, or
• Click the file picker to browse your local files.
• For multiple EML files, upload a ZIP archive containing all the files. The folder structure inside the ZIP is preserved in the output.

Upload limits depend on your plan:

• Free tier: up to 100 MB per file.
• Standard plan: up to 50 GB per file.
• Enterprise plan: up to 50 GB with priority processing.

All uploads are encrypted with TLS during transfer.

Step 3: Wait for Processing

After upload, the server parses your source file and converts it to the target format. A progress indicator shows the conversion status. Processing time depends on file size:

• Under 100 MB: typically under 1 minute.
• 1-5 GB: a few minutes.
• 5-50 GB: 10-30 minutes depending on the number of messages.

You can close the browser tab and return later — the conversion continues in the background.

Step 4: Download the Result

When processing completes, a download link appears. Click it to download the converted file:

• PST output: a single .pst file.
• EML output: a ZIP archive containing .eml files organized in folders.
• MBOX output: one or more .mbox files.
• MSG output: a ZIP archive containing .msg files.

The download link remains active for a limited time. After that, the file is automatically deleted from our servers for your privacy.

Step 5: Open in Your Email Client

• Outlook: File, then Open & Export, then Open Outlook Data File (for PST files).
• Thunderbird: Use ImportExportTools NG add-on for MBOX import, or drag EML files into a folder.
• Apple Mail: Double-click EML files, or use File, then Import Mailboxes for MBOX.
• Gmail: Import via Thunderbird and IMAP. See How to import PST to Gmail.

Security and Privacy

MailtoPst is designed with privacy at every step:

• TLS encryption for all file transfers (upload and download).
• EU-based servers for data processing — your files never leave the European Union.
• Automatic deletion — files are removed from servers after conversion. No long-term storage.
• GDPR compliant — full compliance with European data protection regulations.
• No human access — your files are processed by automated systems only.

Account and Billing

• Free tier: 100 MB of conversion credit. No credit card required. Perfect for testing.
• Standard plan: monthly subscription with generous conversion limits for regular users.
• Enterprise plan: high-volume processing up to 50 GB with priority queues.

All payments are processed securely through Stripe. Invoices are available in your account dashboard.

Frequently Asked Questions

Do I need to create an account?

You can try the free tier without creating an account for quick conversions. Creating an account lets you track conversion history and manage your subscription.

Can I convert multiple files in one session?

Yes. Upload files one at a time, or bundle multiple EML files into a single ZIP archive. Each upload is a separate conversion job.

What if the conversion fails?

Conversion failures are rare but can happen with severely corrupted files. If a conversion fails, you receive an error report explaining the issue. Common fixes include repairing the source file or splitting a very large file into smaller parts.

Is there an API for automated conversions?

Contact the MailtoPst team for information about API access for bulk or automated conversions.

What browsers are supported?

MailtoPst works in all modern browsers: Chrome, Firefox, Safari, Edge. No plugins or extensions required.

Upload your file now and convert your emails in minutes. Try free — no credit card required.