How to Open Winmail.dat to Outlook with Complete Information ?
You can open winmail.dat files in Outlook by converting them to PST (for Outlook on Windows) or OLM (for Outlook on Mac) using the Turgs Winmail.dat Converter. The tool extracts the original email content and attachments and converts them to the format your Outlook version needs.
Receiving a winmail.dat attachment in Outlook is a classic sign that the sender’s Outlook is configured to use Microsoft Rich Text Format (RTF) encoding, which triggers TNEF (Transport Neutral Encapsulation Format) packaging for the email content.
The irony: you’re using Outlook, the same product that created the winmail.dat, but an older or differently configured version that can’t read it. Here’s how to fix that.
Why Outlook Receives Winmail.dat Files
Winmail.dat files appear when the sender uses Outlook with Rich Text Format enabled for outgoing messages, and the recipient’s email client or server doesn’t understand TNEF encoding.
This can happen between different Outlook versions, between Outlook and Outlook.com (which is IMAP-based), or when emails pass through mail servers that strip or mishandle TNEF data. Even if you’re using Outlook 2019, you can receive winmail.dat files from senders whose Outlook is configured differently.
One thing I see constantly overlooked: if you receive winmail.dat files from a specific sender regularly, the fastest fix isn’t the conversion tool. It’s adding that sender to your Outlook contacts and setting their contact record’s email format to “Let Outlook decide” or “Internet Format.” This tells your Outlook to request plain MIME from that sender, bypassing TNEF entirely. The conversion tool is your backup for files you’ve already received or from senders whose settings you can’t control.
The Winmail.dat Converter by Turgs extracts the content from the TNEF package and converts it to a format your Outlook version can import. You can convert to PST for Outlook on Windows, or to OLM for Outlook on Mac.
Method 1: Open Winmail.dat in Outlook for Windows (via PST)
If you use Outlook on Windows, convert the winmail.dat to PST format, then import the PST into Outlook.
Step 1: Launch the Winmail.dat Converter on your Windows PC.
Step 2: Add your winmail.dat files using the Add File button or drag them into the tool interface.
Step 3: Select PST as your output format. Choose PST from the list of saving options. PST is Outlook for Windows’ native format.
Step 4: Click Convert. The tool creates a PST file containing the extracted email content and attachments from the winmail.dat. This process completes in under a minute for most winmail.dat files.
Step 5: Import the PST into Outlook. Open Outlook, go to File > Open & Export > Import/Export > Import from another program or file > Outlook Data File (.pst). Select the converted PST and import it. Your winmail.dat content now appears as a regular email in Outlook.
Method 2: Open Winmail.dat in Outlook for Mac (via OLM)
If you use Outlook for Mac, convert winmail.dat to OLM format instead. OLM is Outlook for Mac’s native archive format.
Steps 1 to 3 are identical to Method 1, except in Step 3 you select OLM as the output format instead of PST.
Step 4: Click Convert to create the OLM file. The tool generates an OLM archive containing the winmail.dat content.
Step 5: Import the OLM into Outlook for Mac. Open Outlook for Mac, go to File > Import, select Outlook for Mac archive (.olm), and choose your converted file. The email content and attachments from the winmail.dat appear in Outlook for Mac.
Key Features of the Winmail.dat Converter
Converts to PST and OLM. Handles both Outlook for Windows (PST) and Outlook for Mac (OLM) as conversion targets in a single tool.
Extracts all attachments. Every file embedded in the winmail.dat TNEF package comes out as a separate attachment alongside the email body.
Batch processing. Convert multiple winmail.dat files at once without running the tool separately for each file.
Multiple output formats. Beyond PST and OLM, the tool also converts to EML, MBOX, MSG, PDF, and HTML, covering all major email clients and archiving needs.
No Outlook installation needed. The conversion tool runs independently without requiring Outlook to be installed on the machine performing the conversion.
Limitations to Know
Limitations
- The converter runs on Windows only. To convert winmail.dat for Outlook on Mac, run the converter on a Windows machine and transfer the OLM file to your Mac.
- Winmail.dat files with only Outlook-specific metadata (not actual email content) may produce nearly empty PST or OLM files after conversion.
- Calendar invites embedded in winmail.dat convert to standard ICS format. Some complex recurring appointments may lose TNEF-specific formatting details.
- The free trial limits the number of items converted per batch. A paid license is required for bulk conversions.
- Very old winmail.dat files from Outlook 97 or earlier may not convert fully due to TNEF version differences.
- The long-term solution is for the sender to switch Outlook’s outgoing format from RTF to HTML. That eliminates winmail.dat generation completely for future emails.
Frequently Asked Questions
Why am I getting winmail.dat in Outlook when I already use Outlook?
Winmail.dat can appear in Outlook when the sender uses a different Outlook version or configuration, when the email passes through certain mail servers that strip TNEF headers, or when the email is forwarded through a non-TNEF-aware mail relay. It’s a sender-side configuration issue, not a problem with your Outlook.
Can I fix the winmail.dat problem permanently?
Yes, from the sender’s side. Ask them to open Outlook, go to File > Options > Mail, and change “Compose messages in this format” from “Rich Text” to “HTML.” That eliminates TNEF packaging for all future emails from that sender.
Can I open winmail.dat files directly in Outlook 2019 or 365?
Modern Outlook versions (2013 and later) can sometimes decode TNEF automatically when received directly. But winmail.dat files downloaded separately, forwarded, or received through non-Exchange servers still require a converter tool to extract the content.
What output format should I use for Outlook on Windows vs Mac?
Use PST for Outlook on Windows (any version) and OLM for Outlook on Mac. PST is Outlook for Windows’ native data format, and OLM is Outlook for Mac’s native archive format.
Do attachments inside winmail.dat get extracted properly?
Yes. All attachments embedded in the winmail.dat package extract as separate files during conversion. The converted PST or OLM file includes both the email body and all original attachments.
Is there a way to preview winmail.dat content before converting?
The Turgs Winmail.dat Converter shows a preview of the content before you commit to conversion. You can see the email body text and the list of embedded attachments to confirm the winmail.dat contains what you expect before choosing an output format.
