There is software that will open such files — just search for Winmail.dat decoder. And you can open them in Microsoft Word. But you’ll see only a bunch of gibberish.

We keep getting e-mail attachments in winmail.dat files, and can't open them. What's going on? Is there a utility that can extract the attachments from these?

Q. I received e-mail from a relative that says it is in a winmail.dat file. When I try to open the file, I get a message that says something like: "You are attempting to open a dat file. They are used ...

If your e-mail program does not support this particular blend of RTF, you’ll end up with that danged .dat attachment–and no easy way to open it. You have a couple of options.

Letter Opener is a Mail.app plugin which decodes the .dat files inline, so the process is transparent to you, the recipient. The attachments appear like any others, and life is that much easier.

That could be harmful to the computer and the operating system. Q: I have received an email with an attachment called winmail.dat that I am unable to open. Can you tell me how to access this file?

Is anyone else receiving winmail.dat attachments, instead of the real attachment since migrating to Exchange 2010? I've had MS give me 4 different kb's on it and none have resolve the issue thus far.

On the other hand, if you don't want to shell out the cash or deal with the nag screen, you could also download TNEF's Enough, which also lets you open winmail.dat files and is freeware.

If you regularly receive winmail.dat files from business associates, Letter Opener is well worth the investment.

I was confused by your answer regarding winmail.dat. The file cannot be opened traditionally, at least to obtain what the receiver believes to be valuable contents. Rather, it's used internally by ...