Yarn En/Decoding

MetaMail, originally a UNIX program, allows yarn to call external "viewers" to handle various MIME encoded messages. It also allows for saving MIME file. It can be a chore to set up, but is very flexible.

You will need to set up a MAILCAP file to define external programs to handle various MIME types, and set an environmental variable to point to it. Refer to the Yarn documentation which describes MetaMail for more information.

A simple, small, and fast MIME decoder. A good Yarn config setting for this program is as follows (note the bold section is where you set what directory you want to save the MIME decoded files in):

decode-mime=munpack -C e:\directory %f


PGP has become pretty much the de facto standard in e-mail encryption. It is an extremely strong public key encryption system. The Yarn documentation discusses PGP and provides sample batch files to run it. However, I find that the following settings work well without the use of batch files:

   secret-sign=pgp -ast %f -o %o
   encrypt=pgp -eastw %f -o %o
   decrypt=pgp %f -o %o
   decrypt-view=pgp -m %f

Please note that the above settings are for the command line version of PGP. Since PGP 5 (and newer) has been designed for Win32 GUI it can not be used in the above manner to integrate into Yarn. However the recent DOS port (of the International version, at least-- and other new command line oriented versions) will probably still work.

A utility used for decoding MIME encoding in headers as well as quoted-printable message bodies. It also serves as a charset translator, but at the moment only for Polish national chars.

UUDeview is a very intelligent decoder which will decode virtually any ASCII encoding format. It can be used with Yarn to decode MIME encoded attaches with the following setting:

decode-mime=uudeview -i -p e:\directory %f

UUEnview can also be used to UUencode, and other encoding, but can not be directly integrated into Yarn for encoding.