TNEF explained

winmail.dat is a wrapper, not the file you wanted.

Outlook can encode rich-text properties and attachments in Microsoft's TNEF format. Other email clients may expose that container instead of its contents.

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Drop a file to recover attachments

Drop it here or choose it from your computer.

MSGEMLEMLXWINMAIL.DATMBOX

Processed locally. Your file never leaves this browser.

How it works

Three steps. No detour through a server.

  1. 1Identify the TNEF container
  2. 2Decode its message and attachment records
  3. 3Download the original embedded files

The common filename is winmail.dat

It can contain formatting, calendar data, and attachments

Treat recovered files like ordinary email attachments

Straight answers

Common questions

Is winmail.dat malware?

The container itself is a Microsoft email format, but any recovered attachment can carry the same risks as another email attachment.

How can a sender prevent it?

They can send internet-format HTML or plain-text mail instead of Outlook rich text, depending on their Outlook or Exchange configuration.