PST to EML

This tool converts an Outlook PST file into a ZIP archive of individual .eml messages. It preserves the original folder hierarchy so each message appears in the same Inbox, Sent Items, or custom folder structure, and each .eml includes full headers, body (HTML or plain‑text) and attachments. ⚠️ Only PST files without a password are processed; encrypted PSTs must be unlocked first.

Folder hierarchy preserved in the ZIP archive

The converter builds a single .zip file whose internal directory tree mirrors the exact folder structure stored inside the uploaded PST. Each top‑level folder such as Inbox, Sent Items, Drafts, Deleted Items, and any custom sub‑folders appears as a matching sub‑directory, and the root directory is automatically named after the original PST file with the .pst extension removed, so the hierarchy is instantly recognizable after extraction.

Messages are placed in the appropriate directories according to the folder they originated from, and empty folders that contain no messages are omitted from the final archive, eliminating unnecessary empty folders while still preserving the logical organization of the mailbox for seamless import into other email clients or archival systems.

Standard email headers retained

For every exported .eml file the converter writes the core RFC‑822 headers—including From, To, Cc, Subject, and Date—exactly as they were stored in the source PST, ensuring that all recipient information, timestamps, and subject lines survive the conversion without alteration. This fidelity allows the resulting .eml files to be searched, sorted, and displayed by downstream mail programs just as they were in Outlook.

While the Bcc field is intentionally omitted because the .eml format does not support hidden recipient information, all other visible header fields remain intact. Consequently, users can rely on the preserved headers for accurate threading, filtering, and legal compliance without needing any additional post‑processing steps.

Body formats and inline media preserved

If a message in the PST contains an HTML body, the converter extracts the full HTML markup and writes it into the .eml file as an HTML MIME part, keeping paragraphs, headings, tables, lists, inline styles, and embedded CSS exactly as they appeared in Outlook. Plain‑text bodies are also retained as separate MIME parts, so mail clients that prefer plain text can display the message correctly.

Inline images that were embedded in the original message are saved as Content‑ID MIME parts, ensuring that they render automatically within the body of the .eml without requiring external network requests. This approach guarantees that the visual appearance of the email remains faithful to the source, making the converted messages ready for immediate viewing or forwarding.

Attachments included as MIME parts

All file attachments associated with a PST message—whether PDFs, ZIP archives, Word documents, images, or any other binary type—are packaged into the corresponding .eml as standard MIME attachment parts. The attachment data travels together with the email content, creating a self‑contained file that can be opened, saved, or forwarded without relying on external references.

Because each attachment is embedded directly inside the .eml, there is no need for additional companion files or separate directories after extraction. Mail clients that support MIME will display the attachments alongside the message body, and users can download or open them exactly as they would with any native email attachment.

Multiple PST files processed together

When several PST files are uploaded in a single conversion request, the tool creates a distinct top‑level directory for each PST inside the same output .zip. Each directory follows the same naming convention—derived from the original file name—and contains its own replicated folder hierarchy, allowing users to keep the contents of different mailboxes logically separated within a single archive.

The conversion processes each PST sequentially, preserving the order of upload, and the total processing time scales proportionally with the combined number of messages across all submitted files. This design lets power users consolidate multiple mailboxes into one downloadable package while still maintaining the individual structure and content of each original PST.

Limits and scope

Password‑protected PSTs

Processes PST files that are not encrypted; password‑protected files must be unlocked before upload.

Supported PST formats

Accepts both modern Unicode PST files (Outlook 2003 SP3 and later) and legacy ANSI PST files.