Free winmail.dat opener and extractor
Extract attachments and other content from your winmail.dat, ATT00001.dat and TNEF files with this free tool.
Click or drop your file here
No registration or email required. Extraction runs locally in your browser, so your data is 100% private and secure. Your file is never uploaded anywhere.
What is winmail.dat?
Microsoft Outlook can be configured to send email content wrapped in a file called winmail.dat or ATT00001.dat. This uses the TNEF (Transport Neutral Encapsulation Format) to preserve Outlook-specific formatting and features for other Outlook users. If the recipient isn't using Outlook, the file arrives as an unreadable attachment instead of readable content.
This tool extracts the original attachments and message body from a TNEF file entirely in your browser — nothing is uploaded anywhere.
If you have a .msg file instead, use our MSG file viewer. For EML files, use the EML viewer and converter.
A free tool provided by Auth-Email
Auth-Email makes your Gmail, Outlook, or other OAuth 2.0 email account available to any IMAP, POP3, or SMTP email client — no app passwords or special configuration needed.