tnef-filter automatically converts TNEF attachments in an email to
MIME format. It's designed for automated use with a Mail Delivery Agent such as
procmail or maildrop.
For the benefit of search engines, TNEF attachments are typically named
winmail.dat.
Use a recipe like this in your .procmailrc file:
:0 fw
* ^X-MS-TNEF-Correlator:
| /path/to/tnef-filter
As rewriting the emails can break things like DKIM signatures, you might want to write the original emails to a file for backup purposes:
:0 cw :
* ^X-MS-TNEF-Correlator:
| gzip >> tnef.gz
:0 afw
| /path/to/tnef-filter --purge
By default tnef-filter will keep the original TNEF attachment, as it doesn't
convert all the information held within it. If you're not worried about data
loss, or have kept a copy of the original email, the --purge flag can be used
to override this behaviour and remove the TNEF attachment.
tnef-filter is available under the terms of the ISC license, which is
similar to the 2-clause BSD license. See the LICENSE file for the copyright
information and licensing terms.