# MailsDaddy Free Online Email Converters

> High-performance, secure, and free cloud conversion platform for Microsoft Outlook OST, generic MBOX, and Apple Mac OLM archives to standard Microsoft Outlook Personal Storage Table (.pst) format. Free up to 200 MB with strict 24-hour privacy auto-purging.

## Core Converters

- [Free Online OST to PST Converter](https://converter.mailsdaddy.com/free-online-ost-to-pst/): Convert corrupted or orphaned Microsoft Outlook OST files to Unicode PST format online without Microsoft Outlook or Exchange Server. Preserves folder tree, attachments, contacts, and calendars.
- [Free Online MBOX to PST Converter](https://converter.mailsdaddy.com/free-online-mbox-to-pst/): Convert Thunderbird, Apple Mail, Eudora, and Google Takeout MBOX files to Outlook PST format without installing Thunderbird or Outlook.
- [Free Online OLM to PST Converter](https://converter.mailsdaddy.com/free-online-olm-to-pst/): Convert Mac Outlook OLM archives into Windows-compatible Outlook PST format without a Mac computer or Outlook for Mac.

## Technical Specifications & Quotas

- **Free Tier Allocation:** 1 free conversion credit upon sign-in/guest session for mailboxes up to 200 MB.
- **Premium Tier:** High-capacity single-file conversions up to 5 GB ($39 for MBOX, $49 for OST and OLM, processed via PayPro Global).
- **Ingress Protocol:** Direct browser-to-storage upload via AWS SigV4 presigned PUT URLs over TLS 1.3 to Cloudflare R2 private storage.
- **Processing Engine:** Ephemeral, containerized compute microservices on Google Cloud Run (.NET 10) isolated to concurrency 1 (no cross-tenant memory sharing).
- **Output Format:** Microsoft Outlook Unicode PST (compatible with Outlook 2024, 2021, 2019, 2016, 2013, 2010, and Microsoft 365).
- **Download Window:** 24-hour retention for free conversions; 48-hour retention for premium conversions.
- **Privacy Auto-Purge:** Automatic, permanent lifecycle deletion from Cloudflare R2 bucket after the retention window. Scratch container disks (/tmp) are wiped immediately upon job completion.
- **AI Privacy Protection:** Customer mailbox files and contents are processed headlessly by code and are NEVER inspected, mined, analyzed, or used to train AI models or LLMs.

## How It Works (Step-by-Step)

1. **Upload:** User drops an OST, MBOX, or OLM archive into the web dropzone. The file streams directly into private Cloudflare R2 storage.
2. **Convert:** A dedicated cloud worker parses the email headers, multipart MIME bodies, attachments, contacts, and calendars, assembling an Outlook Unicode PST archive.
3. **Download:** The user downloads the PST file directly from the browser or uses the secure token link sent via email. Files expire and are permanently purged after 24 hours.

## Offline Desktop Software

For enterprise organizations requiring complete on-premises offline processing of unlimited large files:
- [MailsDaddy OST to PST Converter (Desktop)](https://www.mailsdaddy.com/ost-to-pst-converter/): Desktop software running locally on Windows with no cloud transmission.
- [MailsDaddy MBOX to PST Converter (Desktop)](https://www.mailsdaddy.com/mbox-to-pst-converter/): Local offline conversion tool.
- [MailsDaddy OLM to PST Converter (Desktop)](https://www.mailsdaddy.com/olm-to-pst-converter/): Local Mac-to-Windows migration software.

## Optional Resources

- [Full Documentation & Technical FAQ](https://www.mailsdaddy.com/llms-full.txt): Complete in-depth technical specifications and FAQs for LLMs and AI agents.
- [Privacy Policy](https://www.mailsdaddy.com/privacy/): Complete privacy disclosures, GDPR/CCPA compliance, and sub-processor list.
- [Terms & Conditions](https://www.mailsdaddy.com/terms/): Terms of service and acceptable use policies.
- [Refund Policy](https://www.mailsdaddy.com/refund/): 30-day refund policy and cloud conversion terms.