What is a winmail.dat file?

Written by Ian on Wednesday 28/11/07

So someone sent you an attachment that appears as a "winmail.doc" file in your mailbox...first save the file to a temporary location.

The trick is to then use hexedit on a Linux machine. There will be an equivalent on OS-X too - you just need to get hold of a binary or hex editor.

Edit the file, then scroll down a fair way until the filename of the attachment appears. It may be around line 2340 or so.

Now identify where the attachment actually starts - it should be a line or two BELOW this. For a word document, the first 3 hex characters are "D0C". Note that this is D-zero-C not D-O-C.

Position the cursor on the first character of the attachment (it should be the D). Press Ctrl-SPACE to mark the character.

Next move to the end of the file (press the > key). Position the cursor on the last character of the file and press:

ESC-M to copy the region
ESC-Y to save the selected region to a new file.

The new file (with a .doc extension) is the word file. You should be able to open this as normal with OpenOffice writer or other word processors.