How to Open Winmail.dat Files on iPhone & iPad (2025 Guide)
Can't open winmail.dat files on your iOS device? This comprehensive guide shows you exactly how to access all hidden attachments in just a few taps. Works with all iPhone and iPad models.
Quick Solution:
Download Winmail File Viewer from the App Store for instant access to all winmail.dat contents.
Get the App NowIn This Guide:
Why You Receive Winmail.dat Files
Winmail.dat files are created when someone using Microsoft Outlook sends you an email in Rich Text Format (RTF). This proprietary format, also known as TNEF (Transport Neutral Encapsulation Format), packages the email's formatting and all attachments into a single file that iOS Mail and most email clients can't open natively.
Common Scenario: Your colleague sends you important documents from Outlook, but all you see is a mysterious "winmail.dat" file that won't open on your iPhone or iPad.
Step-by-Step Instructions to Open Winmail.dat on iOS
Download Winmail File Viewer
Open the App Store on your iPhone or iPad and search for "Winmail File Viewer" or tap the link below:
Open Your Email
Go to your Mail app and find the email containing the winmail.dat file. You'll see it listed as an attachment.
Tap the Winmail.dat File
Tap on the winmail.dat attachment. iOS will show you a preview screen with sharing options.
Select "Open in Winmail File Viewer"
Tap the share button and select "Winmail File Viewer" from the list of apps. The file will automatically open in the app.
View and Save Attachments
All hidden attachments are now visible! You can view, save, or share any document, image, or file that was contained in the winmail.dat file.
Alternative Methods
Method 2: Ask the Sender
Request the sender to resend the email in HTML or plain text format instead of Rich Text Format. They can change this in Outlook's message format settings.
⚠️ Drawback: Requires action from the sender and may not always be practical.
Method 3: Use a Computer
Forward the email to yourself and open it on a Windows computer with Outlook installed.
⚠️ Drawback: Requires access to a computer and is not convenient for mobile users.
Why Winmail File Viewer is the Best Solution
- Instant access - no waiting or forwarding emails
- Works offline - no internet connection needed
- 100% secure - files stay on your device
- One-time solution - works for all future winmail.dat files
How to Prevent Receiving Winmail.dat Files
While you can't control how others send emails, you can share these tips with frequent senders:
For Outlook Senders:
- Go to File → Options → Mail
- In the "Compose messages" section, change format to "HTML" or "Plain Text"
- For individual recipients: Create a contact and set "Internet Format" to "Send Plain Text"
- Disable Rich Text Format for all external recipients in Exchange settings
Frequently Asked Questions
Is it safe to open winmail.dat files?
Yes, winmail.dat files themselves are not dangerous. They're simply containers for email attachments. However, always be cautious about the actual attachments inside, just as you would with any email attachment.
Why can't iPhone open winmail.dat files natively?
Winmail.dat uses Microsoft's proprietary TNEF format, which Apple's Mail app doesn't support. This format is specific to Outlook and requires specialized software to decode.
Will I lose any data when extracting files?
No, Winmail File Viewer extracts all attachments in their original format without any data loss. All documents, images, and files remain intact.
Do I need to pay for the app?
Winmail File Viewer offers a free version with basic functionality. Premium features are available through optional subscriptions for users who need advanced features or unlimited use.
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