How to Convert Outlook MSG Files to JSON

Unlike EML (plain text), MSG is a binary Microsoft format. Parsing it in a script usually means hunting for a library that may or may not handle Unicode, embedded messages and RTF bodies correctly. For a one-off job or a test fixture, converting to JSON is much quicker.

Output example

{
  "subject": "Sign-off on phase 2",
  "from": [{ "name": "Chris Park", "address": "chris@client.com" }],
  "to": [{ "name": "Project Team", "address": "team@example.com" }],
  "cc": [{ "name": "Dana Wu", "address": "dana@example.com" }],
  "date": "2025-02-03T16:45:00.000Z",
  "text": "Confirming we're happy to sign off phase 2 as scoped…",
  "html": "<html>…</html>",
  "attachments": [
    { "name": "phase2-scope.docx", "type": "application/vnd.openxmlformats-officedocument.wordprocessingml.document", "size": 114688 }
  ]
}

• text is always filled in. When the email only has HTML, it's converted to clean text.
• html is null when the email has no HTML version.
• Addresses are SMTP addresses where Outlook stored them, rather than internal Exchange identifiers.

How to convert MSG to JSON with ZapMorph

1. Open the converter

Go to the MSG to JSON converter.

2. Add your MSG files

Drop them in. You can add several at once.

3. Convert and download

Click Convert to JSON.

Use cases

• Test fixtures: realistic email data for unit tests of a mail-processing app.
• Ticket and CRM imports: map from, subject and text onto records.
• Compliance review: load a folder of MSG evidence into a script and filter by sender or date.
• AI pipelines: feed text into classification or summarisation.

Combining many files

Each MSG becomes its own JSON file. To merge them into one array:

jq -s '.' *.json > all-emails.json

Or in Python:

import json, glob
emails = [json.load(open(f, encoding="utf-8")) for f in glob.glob("*.json")]

Tips

• Browse the output in the JSON viewer.
• A whole Outlook archive? PST to JSON handles .pst files.
• Want a spreadsheet? MSG to CSV.
• Need attachment files? The Email Attachment Extractor saves them all.

Troubleshooting

"Isn't a readable Outlook MSG file." The file is damaged or not a genuine Outlook MSG.

An attached email is missing from attachments. Emails nested inside an MSG are skipped. Save them separately from Outlook.

Summary

Skip the parsing library. The MSG to JSON converter turns Outlook emails into clean, structured data in seconds.